The World Conker Championships is investigating after the men’s champion was found with a steel chestnut in his pocket.
David Jakins, 82, was victorious in Sunday’s event – it was his first win after competing since 1977.
The veteran player, known as “King Conker”, recorded several victories in which he destroyed the other player’s conker with one hit.
His opponent in the final Alastair Johnson-Ferguson told The Daily Telegraph he raised concerns after his conker “disintegrated in one hit, and that just doesn’t happen”.
A fake steel conker, painted brown, was later found in Mr Jakins’ pocket.
He denied using it during the tournament in Southwick, Northamptonshire, and said he only had it with him for “humour value”.
Mr Jakins, who helped prepare other players’ conkers which are then selected from a sack, also denied any suggestion he marked the strings to highlight harder nuts.
A tournament spokesman told Sky News the steel conker was indistinguishable from a real one, with its weight the only giveaway.
St. John Burkett, from the organising committee, said an investigation was ongoing but current indications suggested no foul play.
“We are currently reviewing video evidence, and have located both the winning conker and the one from the semi-final, which was thrown into the crowd,” he told Sky News.
“We are currently minded to think that the win was fair, and that the steel conker was kept in the pocket throughout, but just need to complete the last parts of the investigation.”
Mr Jakins won the men’s competition but lost in the overall final to women’s champion Kelci Banschbach, originally from the United States, who only took up the game last year when she moved to Suffolk.
The championships have been held since 1965 and organisers say they have raised £420,000 for charity.
This year’s knock-out event, at the Shuckburgh Arms, saw a host of interesting competitors take part in front of an enthusiastic crowd.