The transfer of Michel Vorm from Swansea City to Tottenham Hotspur will be the subject of a hearing at the Court of Arbitration for Sport later this week.
Dutch outfit FC Utrecht claim that they are owed 30% of the fee paid to the Swans by Spurs when the goalkeeper switched South Wales for North London in July 2014.
Utrecht claim that there was a sell-on clause in the contract after Vorm had left them to join Swansea for £1.5m in 2011.
The deal to take Vorm to Spurs happened on the same day as Ben Davies made the same switch, with Gylfi Sigurdsson heading in the opposite direction.
The Dutch international was reportedly given no value in the transactions, which is why Utrecht have not received a sell-on fee, although they have questioned that due to the fact that Vorm had two years remaining on his contract.
The case will now be heard at the Court of Arbitration for Sport on Friday having already been dismissed by FIFA.