West Ham have been charged by the Premier League with breaching the rules when they signed Argentine duo Carlos Tevez and Javier Mascherano in August.
Tevez and Mascherano joined the club in August, but their registration with third party Media Sports Investment may have broken Premier League rules.
If found guilty, the Premiership side, who lie 19th in the Premiership, nine points adrift of safety, could be deducted points. Given their parlous position in the league, a deduction would almost certainly condemn the Hammers to relegation.
Tevez and Mascherano joined West Ham on 31 August from Brazilian side Corinthians, but the deal was brokered by MSI, who owned the rights to the two players.
The club allegedly failed to hand over vital documentation to the Premier League and have been charged under rule U18 concerning the influence of third-party ownership.
Mascherano has since left West Ham and joined Liverpool.