FIFA are investigating a claim by Eintracht Frankfurt against West Ham relating to the transfer of Sebastien Haller.
The German club have lodged a complaint with FIFA that they have not received a sum of £5.4m from the Hammers as part of the deal for the French striker.
In a statement, FIFA said: “We can confirm that we have received a claim from the German club Eintracht Frankfurt against English club West Ham United. The matter is still being investigated and consequently we cannot provide any further comments.”
Sources at West Ham insist the delay came about after an issue between the two clubs and the payment is in the process of being dealt with.
The club will not comment formally on the issue as it is deemed commercially confidential.