World governing football body FIFA is investigating Premier League side, West Ham, over the transfer of Sebastian Haller.
West Ham delayed payment to Eintracht Frankfurt for the transfer of the striker for a contractual dispute between the two sides.
Haller, 26, had cost West Ham £45 million when they signed him from the Bundesliga club last summer with the fee to be paid in instalments. The latest instalment of £5.4million was due on May 15 but was not paid, leading to Frankfurt reporting the matter to the world governing body.
A Fifa statement read: “We can confirm that we have received a claim from Eintracht Frankfurt against West Ham. The matter is currently being investigated and consequently, we cannot provide any further comments.”
Fifa sanctions over the issue range from a reprimand or a warning to a fine or, in the most serious of cases, a transfer ban for up to two windows.
A ban on registering players, however, is usually a suspended punishment or one reserved for repeat offenders. However, the Hammers are confident that the dispute will not reach the stage where sanctions are necessary.
Teams that have been banned before on such cases were Chelsea who was handed a two-window transfer ban, AS Roma (when they bought French centre back Philippe Mexes in 2004), Sion, FC Barcelona, Real Madrid and Atletico Madrid.