Ligue 1 side FC Metz have blasted West Ham United after a proposed deal collapsed for Senegalese striker Diafra Sakho.

The 24-year-old looked set for a €4m move to Upton Park when the two sides agreed a transfer last week but Metz called the deal off after claiming the London side attempted to change the terms of the deal.

According to the French club, the Hammers initially agreed to sign Sakho in a permanent deal but then requested a season-long loan move with a view to a transfer.

A statement on the Metz website read: “The English club decided to propose to FC Metz a loan with option to purchase, which absolutely does not correspond to the expectations of FC Metz and contradicts all terms and conditions that had been validated specifically late last week between the two clubs.”

Metz also threatened to report the Irons to football authorities after pulling the plug on the deal.

The statement said: “FC Metz regret a clear lack of serious and unacceptable disrespect from West Ham against FC Metz but also in respect of the player.

“As a result, FC Metz reserves the right to address international sports courts to assert their rights and defend their interests.”

Sakho will now return to Metz after originally being given leave from his Ligue 1 duties to travel to England for a medical.