Carlos Tévez joined Manchester United players celebrating their title success at the Les Ambassadeurs casino in Mayfair, Central London, on Wednesday, but West Ham United will be banking on their forward hitting the jackpot in the match between the teams, the last of the season, at Old Trafford on Sunday.

Tévez’s six goals in the past nine matches have dramatically shortened the odds of West Ham avoiding relegation but have left the “Gang of Four” clubs questioning whether they have had a fair roll of the dice.

In a letter obtained by The Times, Wigan Athletic, Sheffield United, Charlton Athletic and Fulham have formally asked the FA Premier League to provide the proof that Tévez has been eligible to play in the past two matches after the FA hearing into his transfer. The clubs also asked whether the League has contacted Media Sports Investment (MSI) and Just Sport (JSI), who own the rights to Tévez, to ascertain whether the companies have given permission for the contract to be terminated.

“Have you obtained confirmation from a suitable independent legal source that West Ham’s assertions are well founded?” the clubs said. “Have you required sight of all relevant correspondence between the parties? Have you been given access to all relevant documentary materials, including any statements of the position of MSI and JSI?”

The four clubs gained the support of Middlesbrough, who were relegated in 1997 after being docked three points for failing to play Blackburn Rovers because of illness and injury. “I have made our views known to the Premier League as to how lenient we feel West Ham’s penalty was,” Keith Lamb, the Middlesbrough chief executive, said. “Why has it taken from January to April to investigate and judge on it? It’s been dealt with in a very poor way by the Premier League. I’ll be smiling on Sunday if West Ham are relegated.”

Dave Whelan, the Wigan chairman, has said that he wants Paul Jewell to remain as manager next season. Jewell may assess the situation if Wigan are relegated. “Paul can stay here with me as long as he wants,” Whelan said. “He’s one of the best managers in the Football League.”