Players' chief Gordon Taylor has raised doubts over a £50,000 match-fixing claim.
A report has claimed that a player agreed to get himself sent off and persuaded three team-mates to get booked in a specific game in return for a bookmaker writing off his £50,000 gambling debts.
But Taylor, chief executive of the Professional Footballers' Association, believes the incident could have been over-elaborated for effect.
He said: "It's disappointing to have this story put in the public domain and leave a cloud hanging over the game, and I would imagine the FA are asking Sporting Chance to be more forthcoming.
"I find it beyond the realms of credulity that a player would approach three others and ask them to get themselves booked.
"It would get around the rest of the team and get back to the manager, there would be fines for players who got booked. I find it beyond belief.
"We support that clinic and their attempts to get players on track and it is disappointing that something like this should emanate from them.
"I do think in such seminars that stories can get over-elaborated for effect."