Premier League bosses have been accused of failing to take any action over Owen Oyston's ownership of Blackpool FC - despite ruling he was unfit to run the club.
The convicted rapist was banned from being the Seasiders' owner and director after the club was promoted to the top flight in 2010, according to a report in The Guardian.
It said Richard Scudamore, the league's chief executive, ordered Oyston to get rid of his shares and thought he had done so, but it was never done.
Oyston continues to own the club, which now plays in the lower echelons of the football league.
Its governing body, the English Football League (EFL) has come under increasing pressure to act in recent weeks, even allegedly receiving a letter from former director Karl Oyston, claiming his father Owen was not fit to run it.
Christine Seddon from Blackpool Supporters' Trust (BST) said: "It should be investigated. If they have made this sort of howling mistake for us, what else have they done?
"We are not in the Premier League anymore but the EFL also should be acting on this. If he was not fit and proper for the Premier League, why is he in any league?
"The simple fact is after what came out in court last year, and the fact he is a convicted rapist, he should not be in a million miles of a football club, and the football authorities have stood by and let it happen."
The Guardian claims Mr Scudamore agreed its fit and proper persons rule would be complied with if Oyston gave his shares to Karl and 'assumed that had been agreed'.
Oyston protested against a 'large tax bill' but was later ordered to do it anyway, the paper said.
Weeks later, the club was relegated out of the Premier League, which said Oyston would not allowed to be owner should the club be promoted again, it added.
The Premier League declined to comment this afternoon .
The 'fit and proper person test' came in 14 years ago, banning people from being owners or directors if they have unspent criminal convictions involving dishonesty, The Guardian said.
It said Owen's conviction remains unspent.
The EFL said any conduct prior to 2004 would not be taken into account, which differed to the Premier League's stance, it said.
The Latvian, who is banned from holding high office at an English club, confirmed to The Gazette he is 'in the process' of reversing his disqualification after meeting with the EFL last week.
Blackpool FC confirmed last September that Belokon had failed the EFL Owners’ and Directors’ Test after being handed a 20-year prison sentence in Kyrgyzstan for money-laundering and tax evasion.
Belokon, who had resigned as a director at the club the previous month, denies any wrongdoing.
The Oystons were ordered to buy out Belokon for £31.27m in November after a court decided they illegitimately stripped the club of cash following their 2010 promotion.
Days later, the club was put up for sale, and the hearing triggered a series of top level changes at the club, which saw Karl leave his position as chairman. He was replaced by Natalie Christopher, Owen's daughter.
Owen's grandson Sam was also briefly chief executive.