Ligue 1 side FC Nantes have lodged a complaint with FIFA over the first payment in Emiliano Sala's transfer to Cardiff City which has been delayed.
The Argentine striker lost his life on January 21 after the light aircraft he was travelling to Cardiff in, after saying his goodbyes to his teammates at the Stade de la Beaujoire, crashed into the English channel.
Cardiff City were due to make the first of three instalments of the £15m fee to FC Nantes on February 20 but agreed that the deadline could be pushed back by a week. But the Bluebirds are now withholding the first payment until they cleared any "anomalies" around the deal.
"We can confirm we have received a claim," a FIFA spokesperson said on Tuesday, quoted by the BBC. "We are looking into the matter."
Sala's former side Bordeaux, who played FC Nantes most recently in Ligue 1, are entitled to 50% of the transfer fee due to a sell-on clause when the Argentine swapped southwestern France for Brittany in 2015.
An initial search for the aircraft carrying Sala and his pilot David Ibbotson was initially called off by Guernsey police three days after the plane went missing over the channel.
It was restarted when a privately-funded crew worked alongside the Air Accidents Investigation Branch (AAIB)'s Geo Ocean III.
Soon after a body was discovered in the wreckage which was later confirmed to be that of Sala. The search for Ibbotson is still ongoing, although the BBC confirmed there was "no sign" of a body within the wreckage after a search from two divers on Wednesday.