Nantes have appealed to FIFA after Cardiff City failed to meet the deadline for the first £5million payment of Emiliano Sala's transfer fee.
The first payment for the Argentine striker, who died in a plane crash in the English Channel on January 21, had been due on Tuesday.
But the Premier League club are withholding payment until crash investigations were completed and they were satisfied over 'anomalies' around the deal.
Sala's transfer fee of £15m had been due to be paid in three instalments and Nantes wrote to Cardiff on February 5 requesting the first of them by February 20.
The clubs later agreed to extend the deadline but that has now passed without movement on Cardiff's side.
Nantes have now contacted world football's governing body to arbitrate in the matter.
A FIFA statement read: 'We can confirm that we have received yesterday evening a claim from FC Nantes against Cardiff City in connection with the transfer of Emiliano Sala.
'We are looking into the matter and consequently we have no further comments at this stage.'
Sala, 28, was Cardiff's record signing and was due to report to the club for training on January 22.
But the Malibu Piper N264DB light aircraft carrying Sala and pilot David Ibbotson from Nantes to the Welsh capital went missing near the Channel Islands on January 21.