Katrice Lee was snatched in the blink of an eye on her second birthday when her mum turned her back for a moment at the supermarket - and hasn't been seen since... But 42 years on, her family are still searching and are haunted by anger and guilt

There was a time when the search for Katrice Lee was a fun, joyous thing. Her big sister Natasha remembers the ritual of 'silly hide-and-seek games' when Katrice was a toddler.

Sometimes Katrice — five years younger — would be there to meet her as she got off the school bus, but often she would get home to discover her little sister hiding behind the curtains for Natasha to 'find'.

'Of course, her feet would always be poking out the bottom,' Natasha recalls.

If only it were so easy now. It is hard to believe, given the vividness of her family's memories of her, but it is 42 years since Katrice Lee simply vanished. Her family have never stopped looking for her.

Natasha tells me that when she got married a few years ago, she had a tiny red button from Katrice's cardigan sewn in her wedding dress, 'so that it would sit near my heart. She should have been walking behind me, as a bridesmaid. All I had was a button.'

The case of Katrice Lee is one of the most baffling and heartbreaking Missing Person stories in living history.

How can a child simply vanish in a matter of minutes?

Yet it happened, in 1981, on Katrice's second birthday, of all days, on a trip to the supermarket with her mother and auntie to buy party supplies.

The family were living in British military accommodation in Germany at the time, and the trip to the local NAAFI store was a routine one.

Except on this particular November day, Katrice's mother, Sharon, forgot to pick up crisps, so dashed back to get some, leaving her in the care of her aunt — or so she thought. In the few minutes it took her to return, Katrice was gone. Each adult thought the little girl was with the other.

Nowadays the disappearance of a British toddler from a supermarket would be front page news, with every twist and turn in the ensuing investigation followed. The politest thing the family can say about that today is: 'What investigation?'

At first, it was assumed — by the Royal Military Police which headed the hunt for Katrice — that the child had simply wandered off and drowned in a nearby river. Yet no body was ever found, and by the time it was acknowledged that she could have been abducted, as her family always believed she was, it was too late.

Witness statements were not taken until weeks later — even years later in some cases; roads were not closed, nor Katrice's description circulated.

It must be the most horrific situation for any parents to be trapped in, but imagine being the remaining sibling, particularly if you blamed yourself for Katrice's disappearance, as Natasha always has done.

Then aged seven, she refused to go to the NAAFI store that fateful day. 'Which meant I wasn't around to do what a big sister should do — look out for her,' she tells me.

She has been searching ever since, desperate for her family's story to be concluded. 'One way or another,' she points out, lest you think she is the sort to cling only to fairy-tale endings.

Now there has been a particularly poignant twist in this awful story. Richard Lee, the girls' father, continued to serve in the Army until 1999, notching up 34 years of distinguished service. Last week, frustrated by the perceived lack of support the family have received from the military and the Government, he declared that he will hand his medals back, in protest.

A march on Downing Street is planned for next year, when he will make the symbolic sacrifice.

The family's issues? There are many, but the most important is that they want an independent inquiry, and for the search for Katrice to be handed to a civilian police force — as would have happened had the family been in Germany on holiday.

'This has always come under the jurisdiction of the Royal Military Police, who were out of their league from the start,' argues Richard. 'The lies and the cover-ups since have beggared belief, and all the while there is a chance that Katrice is still out there, living with another family, unaware that she is even Katrice.'

Natasha adds: 'My dad was prepared to give his life for Queen and Country, so those medals mean everything to him. But Katrice, and the truth about what happened to her, means more.'

Richard and Sharon split up in 1989, their marriage unable to bear the strain associated with a missing child. But they remain united in their search for Katrice. 'Both my parents are in their 70s. I don't want them to go to their graves never knowing what happened,' says Natasha.

All three agree to speak to me — patiently answering questions that are being asked four decades too late — and what emerges is a story of a family destroyed.

At her home in Gosport, Hampshire, Sharon produces a clutch of photographs of Katrice that even the family didn't know existed until a decade ago. 'My ex-husband's sister died, and these were brought out,' she explains. 'All these years and we'd only had a handful of pictures. That makes these so precious.

'I got such a jolt when I saw this one. See that expression on her face? That's the way I always remembered Katrice. She didn't have that look in the pictures we had previously. I only regret that we didn't have these pictures when we had artist's impressions done of how Katrice might look now. Did we send pictures out into the world that even Katrice wouldn't recognise as herself if she saw them?'

If Sharon and Richard's lives were derailed by the disappearance of Katrice, their eldest daughter's was shaped by it.

'When I was seven I was told to pray to God, and if I prayed hard enough he would bring Katrice home. So I prayed and prayed, and he didn't bring her home. I don't believe in God now,' Natasha says.

While her parents clearly tried to protect her, they could not. Her most vivid childhood memory is of her mother screaming on the day Katrice disappeared. 'I will never forget the sounds she made. They haunt me.'

She talks of a recurring childhood dream where she runs towards a pram in excitement, and turns back the hood — only to find Katrice's head.

'You were quite a disturbed child, Natasha,' says Sharon.

'That's what happens, Mum,' Natasha replies.

Only in recent years has Natasha accepted that she needed counselling to help her process the loss of Katrice. 'I don't know who I would be if it hadn't happened,' she says. 'That's a big thing to live with in itself.'

We return to November 28, 1981. Richard — then a sergeant in the King's Royal Hussars — had driven Sharon, her sister Wendy (who was visiting for her niece's birthday) and Katrice to the store, and waited in the car for them. It was busy because it was the last Army payday before Christmas and Katrice — 'who was at that age', explains her mother — refused to go in the trolley. Only when she was at the checkout did Sharon make the snap decision to dash back for crisps.

'Did she wander after me? Go in the other direction? We don't know,' she says. 'The fact is, one minute Katrice was there; the next she wasn't.' The following hours were a blur. Both the Royal Military Police and local police were quickly on the scene, but seemed convinced that they were dealing with a lost, not abducted, child.

'They kept asking if she liked ducks, and I said yes, all children like ducks,' says Sharon. 'I wish I hadn't. They were fixated on the belief she had fallen in the river. My feeling is they made a huge mistake — and by the time they realised it, the cover-up had started.'

Little wonder they are bitter about their treatment at the hands of the Army. They were left floundering. Appallingly, they still haven't been allowed to see the full Army files, but Sharon is aware of one report where she was described as 'a woman of limited intelligence'. She isn't, patently. But even if she were, why should that be relevant?

'They tried to blame me,' she says. 'Whether it was to cover up their own failings, I don't know, but there certainly was no 'help' there. We were distraught, but it took six weeks for the Army liaison person to actually come to see us. On the night Katrice disappeared I had to be sedated, but they wouldn't even send out an Army doctor to give me the jab; I had to go to the clinic. The Army washed their hands of us.'

Natasha blames them for trying to stop the story becoming the talking point it needed to be.

'The British Army had one of the biggest PR departments of any, even in those days. It could have pulled out all the stops to raise awareness, had it wanted to. But it didn't want to know.

'At one point Dad was told, point blank, that the Press weren't interested in Katrice. He said: 'I beg to differ. I have a German journalist who wants to speak to me about what has happened, and I am seeing him tonight.'

'His superior lifted a book on Army rules and regulations and said he should throw it at him.'

Richard speaks to me separately from his home in Hartlepool, and goes further. 'It continued like that. I was marked as a trouble-maker.

'When, a few months later, Margaret Thatcher's son went missing [Mark Thatcher disappeared for six days in 1982 while competing in a motor racing rally in the Sahara desert], I wrote to her, saying 'Welcome to the parents-of-the-missing club' and asking for her help with Katrice's case. I was reprimanded for it.'

He never got a reply from Mrs T, and continued to write to successive Prime Ministers over the years.

Just over a decade ago, and largely due to the perseverance of the family, the case was reopened when the Ministry of Defence finally acknowledged that its original investigation was 'flawed'.

In 2018 a team of Army divers did trawl the river near where Katrice had gone missing, but no body was discovered. It was no surprise to Richard, who argued that she would never go near a river. 'She hated water. She hated even being in the bath. No one ever listened.'

He maintains that 'someone walked out of that supermarket with Katrice'.

An arrest was made in the case, but no charges were brought. Successive moments of hope that, as Richard puts it, 'there might be a breakthrough', have stalled.

Last year a long-promised 'father-to-father' meeting with the then PM Boris Johnson did happen, but Richard says: 'Nothing came of it. I wrote afterwards, asking for an inquiry, and for Katrice's case to be investigated by a civilian force, as it would have been if we'd been any other family.'

He never got a reply. 'Politicians move on,' he says. 'We cannot.'

Sharon knows she is the woman every mother dreads becoming. She has met Kate McCann (mother of Madeleine, the three-year-old who disappeared while on a family holiday in Portugal in 2007) a few times now, through her charity work, and says she was hurt when Kate first refused to meet her.

'When we did meet she apologised, but said she hadn't been able to bear the thought that one day she would be me, still not knowing 30 years on. I understand that.'

Sharon's is an impossible burden. 'People say I should move on,' she says. 'But you can't if you don't know. How do you grieve for a child when you do not know if they are alive or dead?'

The attention the family have had from members of the public has been a double-edged sword.

Over the years they have been targeted by trolls. In 2013 a woman called Donna Wright, from County Durham, was prosecuted for stalking after subjecting Natasha and her mum to a cruel deception in which she pretended to be Katrice and then bombarded them with hateful messages. 'She said to my mum — and I will never forgive her for this — 'I have four kids. I managed to go the supermarket without losing any of them.' '

There have been similar trolling incidents since, with yet another one just a few weeks ago. 'This one has been DNA-tested and she is not Katrice, yet she is convinced she is,' says Natasha.

Their Facebook group is no longer an 'open' one, accessible by all. Members wanting to join have to be approved. Yet they need the internet — and its myriad complications — more than ever.

'In some ways I want to switch it all off, but we still need people to help,' says Natasha. 'I know, even as I'm dreading the next message dropping in, that it could be the one. It could be Katrice.'

• Anyone with information about Katrice's disappearance in 1981 can contact the Royal Military Police on social media site X at @operationbute, or by phone on 0800 616888.