An Antiques Roadshow guest was interrupted by an expert who urged him to take stock of the significant value of his rare item.
Expert Jon Baddeley raced to advise the participant how he could make a 'small fortune' on the latest episode of the BBC show.
The fine art auctioneer headed to Clissold Park in North London, where he met a guest owning a stunning collection of vibrant music posters from the 1960s.
Observing the vintage items, Jon said: 'So you've kindly brought us today a collection of psychedelic rock 'n' roll posters. What I notice immediately is they're all signed by the same artist, how so?'
'Because I am that artist,' the guest replied.
An Antiques Roadshow guest was interrupted by an expert - who urged him to re-consider the significant value of his rare item
Expert Jon Baddeley raced to advise the participant he could make a 'small fortune' - although he wasn't aware of its worth (pictured)
'So I grew up just north of San Francisco and I was about 19 when I went to work for the Fillmore Auditorium, and some of these posters were for them.'
Jon looked interested as he asked: 'What was it like out there? I mean, it must've been really exciting. That was the centre for hippie-dom flower power.'
He replied: 'Yes, it was. I can remember and I'm afraid I indulged a bit too much.'
But the collectables expert wasn't done scrutinising and continued: 'The two posters near you, they're similar but slightly different, why's that?'
The guest explained: 'Well, it was a Blues show. I did this artwork of a complete - Blues musicians at the top, a street scene with people dancing (at the bottom).
'But Bill Graham, who ran the Fillmore Auditorium, had had lots of trouble with the police, and he thought that would be provocative,' he added, pointing to a depiction of a policeman on the original poster.
He revealed that eventually, the poster was altered by the printer, meaning the item was one of a kind.
Roadshow veteran Jon (pictured left on the show in 2019) has been on the show since 1993 and he is the managing director of the international auctioneers Bonhams Knightsbridge
'Then that went to production and around town?', Jon asked, to which the guest quipped: 'And it is still on t-shirts to this day.'
'When you talk about value... individually these all are in incredibly good condition, they belong to the artist and they're very rare,' the expert claimed.
'So they're gonna be worth £200, £300, £400, £500 - maybe even up to £1,000. But the great value is the one at the end because that is one of one, it's the only one known in the world, so that could be worth £2,000 or £3,000.'
Astonished by the unexpected revelation, Jon urged him to 'go home' and seek the original piece of art.
'But more interestingly, you also own the original artwork so please, please, please go home and see if you can find them because they could be worth many thousands each!' he concluded.
Jon is an Antiques Roadshow veteran, who has been featured on the beloved BBC show for two decades.
He is an authority on scientific instruments and collectables, a broadcaster and an author, as well as a fine art auctioneer.
Trained as an engineer, Jon is the managing director of the international auctioneers Bonhams Knightsbridge.
The TV star joined Antiques Roadshow in 1993 and one of his most memorable moment was when the show whisked off to Australia - where he iconically got to hold a replica of the Wimbledon Championship Cup.
Another guest was left speechless on the show recently after discovering the huge value of his 'hugely important' memorabilia from iconic sci-fi movie Blade Runner
One man brought along a huge collection of memorabilia from the Harris Ford (pictured) starring 1982 movie, which had been collected by his father, and featured costumes and scripts
He explained that his father first began collecting posters but as his 'passion grew' he went 'hardcore' by seeking out bigger items from the film's crew
Another guest was left speechless on the show recently after discovering the huge value of his 'hugely important' memorabilia from iconic sci-fi movie Blade Runner.
One man brought along a huge collection of items from the Harris Ford starring 1982 movie, which had been collected by his father, and featured costumes and scripts.
He explained that his dad first began collecting posters but as his 'passion grew' he went 'hardcore' by seeking out bigger items from the film's crew.
Expert Jon was flabbergasted to see the extraordinary items, including director Ridley Scott's own paper work from the production, and concluded 'thousands of people' would to see it in a museum.