The Hammers were fined £5.5m but weren't deducted points.
A statement read: "The Premier League and the FA are to institute a joint inquiry into the views expressed by the Independent Arbitral Tribunal chaired by Lord Griffiths in September 2008, which dealt with a compensation claim by Sheffield United against West Ham United brought under FA Rules.
"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."West Ham also have commented via their official website. They 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."