The charges, which relate to the part-ownership of the Argentinians by an investment company, have left the east London club facing a possible points deduction or, at least, a hefty fine.

The league's rules forbid the ownership of players by third parties who might be able to influence a club, and forward Tevez and midfielder Mascherano were part-owned by Media Sports Investment, the company run by Iranian-born businessman Kia Joorabchian who then became involved in a takeover attempt for the club.

After seeking legal advice West Ham say they can demonstrate that MSI's part-ownership of the players had no influence over the club because not only did then-manager Alan Pardew not pick the duo very often, but Joorabchian's takeover attempt also failed.

West Ham said in a statement: "In light of the legal advice received, the club will vigorously defend itself against the charges and provide a detailed response as requested by the Premier League within the time allowed."

The transfers, which were completed on the final day of the August 2006 transfer window, were negotiated by former chairman Terence Brown and managing director Paul Aldridge, both of whom have left since the takeover by current chairman Eggert Magnusson.

The other charge relates to allegedly failing to provide the correct documents to the Premier League though Aldridge has claimed he handed over all those he believed were necessary.

The charges had been expected by West Ham but the whole issue is the last thing the relegation-threatened club need at this time.

West Ham would certainly appeal against any points deduction and will claim they have acted in good faith ever since Magnusson took control in December.

The current chairman has admitted however that he would never have entered into the sort of transfer agreement that brought the players to Upton Park on transfer deadline day last August, and if the charges are proven then the club could take legal action against Brown and Aldridge.

The Premier League outlined the charges in a statement which said: "It is the Premier League board's complaint that there were agreements in relation to both these transfers that enabled third parties to acquire the ability materially to influence the club's policies and/or the performance of its teams in League matches and/or the competitions set out in Rule E10. The board's view is this constitutes a breach of Rule U18.

"Furthermore at the time of the transfer agreements for both Carlos Tevez and Javier Mascherano, and until January 24, 2007, West Ham failed to disclose the third-party agreements to the Premier League and/or deliberately withheld these agreements from the Premier League.

"The board's view is this constitutes a breach of Rule B13, which states: 'In all matters and transactions relating to the league each club shall behave towards each other club and the league with the utmost good faith'. West Ham United has 14 days within which to respond to these charges."

Once West Ham have responded, the next step will be for a disciplinary commission to be set up to hear the charges with both sides appointing top barristers to argue the case.

Tevez remains a West Ham player but Mascherano was transferred to Liverpool last month.