West Ham face the threat of further punishment over the Carlos Tevez affair after the Premier League and Football Association announced a fresh investigation into the scandal.
The Hammers were fined £5.5m in 2007 for breaching league rules over third-party agreements in signing Tevez, and the new inquiry will focus on the club's dealings with his representatives after the initial punishment.
It follows an arbitration tribunal chaired by Lord Griffiths who ruled in favour of Sheffield United, and pointed the finger at West Ham chief executive Scott Duxbury. The Blades have lodged a compensation claim of up to £50m.
The new investigation will be conducted by both the FA and the Premier League, who said in a statement: "The joint inquiry will examine whether the conduct of West Ham United immediately after the independent disciplinary commission's decision of 27 April 2007 amounted to further breaches of Premier League or FA rules."
The key point to be investigated is the evidence provided to the tribunal by lawyer Graham Shear, solicitor for Tevez's agent Kia Joorabchian.
Shear said that Duxbury had provided verbal assurances that the third-party agreement still existed - despite the Hammers chief having informed the Premier League that the deal had been terminated.
Griffith said in his findings: "If the Premier League had known what Mr Duxbury for West Ham was saying to Mr Joorabchian's solicitor following the commission decision, we are confident that the Premier League would have suspended Mr Tevez's registration as a West Ham player.
"We have no doubt that those [Tevez's] services were worth at least three points to West Ham over the season and were what made the difference between West Ham remaining in the Premiership and being relegated at the end of the season."
After being told the agreement had been terminated, the Premier League had then allowed Tevez to play for the Hammers in the crucial relegation battle that led to Sheffield United's eventual drop out of the top flight.
The inquiry means West Ham or individuals could face further disciplinary action but the club say they have nothing to hide from the new inquiry.
Club insiders acknowledged the need to investigate Griffiths' findings but say they are convinced they can provide the evidence to prevent further disciplinary action.
And as no recordings of the relevant conversations appear to exist, it will be hard to prove exactly what was said between Duxbury and Shear.
A club statement said: "West Ham United will co-operate fully with the joint inquiry convened by the FA and Premier League.
"We have acted in good faith throughout the various inquiries and investigations into this matter and fulfilled the undertakings given to the Premier League following the initial penalty.
"We have nothing to hide and will ensure that this is once again reflected in our evidence to the FA and Premier League."
The Blades are claiming compensation from West Ham as a result of winning the case, and the final figure will be decided by the tribunal some time in the spring.
West Ham have stood by their chief executive Duxbury since the arbitration tribunal and said his position is not under review.