West Ham United boss Sam Allardyce has admitted that he would be "powerless" to stop Mohamed Diame leaving the club in January.

The 25-year-old joined the Hammers on a free transfer in the summer, but his form has reportedly attracted the interest of a host of European clubs.

"I don't disclose players' contracts publicly. There's always a situation where you're powerless to keep a player because of the size of the price," Allardyce told reporters.

"You can't turn it down. The chairman says, 'Look, we can't turn that down, Sam - we've got to move him on'."

Diame ran down his contract with Wigan Athletic last season.