Shocking new details revealed after footy player, 33, died of horror head knock suffered during game - leaving behind children aged five, four and one

Shocked witnesses have described the death of New Zealand construction worker Cory Heather as a 'freak accident' after he died during a rugby match.

The 33-year-old father of three died surrounded by his loved ones just hours after suffering a severe brain injury in a head knock sustained during a game of rugby in New Zealand.

Cory Heather was playing for the Beachlands Maraetai Club in Auckland on Saturday when he reportedly took a knee to the head that left him unconscious.

A rescue chopper was called to the scene at Te Puru Park on the city's eastern outskirts and he was flown to Auckland City Hospital in critical condition.

Heather's mother Donna, partner Rachel Hurcombe and their three young children were watching the game. 

Now spectators have come forward to describe the shocking incident, saying it looked like a regulation tackle.

Beachlands resident Gareth Price was at Te Puru Park watching his young nephews play and decided to stay and watch the seniors match. 

'There was a bit of hype. Everyone was looking forward to it,' he told Stuff.

'He had caught the ball upright. A guy came through and tackled him. There was no malice in it, it was a good, hard tackle, it was a good, hard game.'

But then Heather didn't get up and the crowd quickly saw that something was terribly wrong. 

'We didn't realise how serious it was, then they started doing CPR and we were like - What the hell is happening?' Price said.

'When you see CPR, you know it's serious.'

Price said Heather was communicating with first responders when they arrived, including volunteer fire brigade members and a medic who was playing soccer on another field. 

 'Anyone who had any skills came over.'

That included Heather's stricken partner, who onlookers said also tried to resuscitate him.

'Hurcombe was pretty amazing, she was a bit of a rock... She had her wits about her and was in control, doing the best she could,' Price said. 

His family agreed to turn off his life support on Sunday. 

Now a fundraiser has been posted on the Givealittle website, a platform like GoFundMe, to raise vital funds for Rachel and Heather's children.

More than $115,000 had already been raised at the time of publication.

The fundraiser has been set up by friends of the family Candice Attwell and Ashleigh Cometti.

'On Saturday 27th April, Cory Heather sustained a severe brain injury during a rugby game. Surrounded by his family and friends, Cory sadly passed away on Sunday evening,' the appeal reads.

'A much-loved partner to Rachel, hands on father to his three children Stevie (5), Benji (4) and Louie (1), and a cherished friend to so many. A bright spark who lead an exceptional life and will be so dearly missed. We love you forever, fly high Cory.

'If you are willing and able to support, we would appreciate donations for Rachel and her children during this heartbreaking time.'

There has been enormous support already, with several large donations from contributors that wish to remain anonymous.

There are also plenty of message of support for the grieving family.

'Thinking of you Rachel & family. Cory was an incredible person to work alongside and realise projects with,' Nathan and Ella posted.

'He touched our lives and made our work as architects a truly rewarding experience. Above all else, he had become a friend to us both and it was a pleasure to hear him speak of family and his love for you all. 

'Things will not be the same on site without his presence and we wish you all the aroha and support in this difficult time.' 

The match Heather was playing in was weight-restricted, with no player over 85kg allowed to compete.

'Cory was a much-loved member of the Senior Under 85kg team, the Club and wider community,' Beachlands president James Gemmell said in a statement.

'The club is heartbroken by Cory's passing. His family, friends and teammates, all have our love and support. 

'We understand the accident will have been traumatic for many involved, including the opposition, match officials and spectators.'

Away from rugby, Heather was a builder and a director of the Woodstar Construction business.

New Zealand Rugby Union CEO Mark Robinson shared the organisation's 'deepest condolences' to Heather's family after learning of the shocking news.

'Please know that all of New Zealand Rugby is with you,' Robinson said in a statement.