Nantes have begun legal action against Cardiff City, demanding the first payments for the purchase of Emiliano Sala, understood to be around £5million, to be transferred immediately, Sky Sports reports.
Sala and his pilot David Ibbotson have been missing since shortly after their plane took off from France on January 21.
The Argentine forward had just signed for a record fee for The Bluebirds with BBC (Wales) reporting the transfer fee is due to be paid within the space of three years.
Body visible in wreckage of Sala plane in channel
During this game, Cardiff players held up a T-shirt bearing the image of the missing Sala , who never played a game for the club. Investigators say they plan to release an interim report into the accident later this month.
Although Nantes were entitled to the first instalment of Sala's fee by now, Cardiff have been left surprised by the demand given the circumstances and the timing.
Cardiff's first payment would ordinarily be due within seven days of the player signing, but the club do not intend to make any payments until the conclusion of official investigations into the causes of his disappearance.
A source at Cardiff told British media that the Welsh club will honour the contract but only once they have clarified "all the facts".
Will it be a happy Chinese New Year for carriers?
People in China will welcome spring and what it brings along - planting and harvests, fresh starts and new beginnings. In Chinese astrology, each year belongs to a Chinese zodiac animal according to the 12-year cycle.
A search team found wreckage of the plane on Sunday in the English Channel, but bodies have not been recovered or identified.
A body was spotted in underwater images of the wreckage and Britain's Air Accidents Investigation Branch (AAIB) has launched an operation to try and recover it.
Sala was making the trip to Cardiff after the transfer to the Premier League club.
Australia PM tours flood-hit city where two men reported missing
The dam was holding 224% of its capacity Monday afternoon, according to CNN affiliate 9 News , after peaking Sunday night at 247%. One native resident, Erin Hahn , shared pictures of a crocodile sitting in shallow water on the tip of her father's drive.
French club Bourdeaux will receive around 50 per cent of the fee as Sala played for the club between 2012-15 before joining Nantes.