West Ham United could be expelled from the FA Cup by FIFA if they are found to have breached the rules of the selection of Diafra Sakho, according to BBC Sport.

The Senegalese international was called up by his country for the African Cup of Nations in Equatorial Guinea but withdrew due to a back injury.

However Sakho, 25, came off the bench to head in West Ham's winner against Bristol City in the FA Cup fourth round 18 days after he withdraw.

Players are not allowed to play for their clubs whilst they are meant to be on international duty and the matter is now in the hands of FIFA.

Senegal exited at the group stage after finishing behind Ghana and Algeria in Group C and coach Alain Giresse condemned Sakho's withdrawal.

He told BBC Sport: "When you cannot fly for six weeks and then suddenly you're playing a football game, there must be miraculous medicine in England," Giresse told BBC Sport. "I'm surprised to learn he played.

"This sets a dangerous precedent because you're going to have players claiming they cannot catch planes to Africa but who can still play football," he added.

Sakho hit back by writing the a message on his Facebook page: "You doubt my love and my patriotism.

"The dream to contribute to the victory of my country flew for this year but is not dead.

"Never doubt the lion sleeping in me, as I never doubt the passion that burns within you."

West Ham drew West Bromwich Albion at the Hawthorns in the fifth round of the FA Cup, with the tie scheduled to take place on Saturday, February 14.

However if the Hammers are found guilty of breaching rules regarding the selection of a player who should have been on international duty, they could face expulsion from the FA Cup with Bristol City re-instated.

The Football Association have refused to comment on the investigation.