West Ham could face disciplinary action from the Premier League for fielding two ineligible players.
The club are being investigated over the registrations of Argentina duo Carlos Tevez and Javier Mascherano.
The pair joined in August, but their registration with third party Media Sports Investment may have broken Premier League regulations.
If found guilty, the Premiership strugglers could be deducted points.
The Hammers reportedly failed to hand over documentation to the Premier League when the pair were signed and could be charged under rule U18 concerning the influence of third-party ownership.