Nantes have demanded payment from Cardiff City over the £15 million transfer of Argentine striker Emiliano Sala, according to reports.
Sala and pilot David Ibbotson were on board a Piper Malibu aircraft, registration number N264DB, which lost radar contact near Guernsey on January 21.
BBC Wales reports that the French side have called on Cardiff to make their first payment as part of an instalment plan lasting three years.
The Ligue 1 side are believed to have threatened the Bluebirds with legal action if they don’t receive a payment within ten days - but Cardiff are reported to be withholding the first scheduled payment “until they are satisfied with the documentation”.
A source at the club told the BBC they would honour the contract once they had clarified “all the facts”.
Cardiff are said to be “surprised” at the request from Nantes while attempts are ongoing to recover a body from the plane that was carrying Sala and Ibbotson, which was found earlier this week.
Bordeaux are entitled to a portion of the transfer fee - thought to be 50 per cent - as a result of Sala’s time at the Matmut Atlantique stadium.
The plane carrying Sala and Ibbotson, from Lincolnshire, vanished en route to Cardiff after the striker returned to Nantes to say his farewells to his former team mates.