French club Nantes have demanded payment from Cardiff City over the £15m transfer of Emiliano Sala, BBC Wales has learned.
Sala, along with pilot David Ibbotson, was on board the Piper Malibu N264DB which lost radar contact near Guernsey on 21 January.
The Argentine striker was Premier League club Cardiff's record signing.
Cardiff have withheld the first scheduled payment until they are satisfied with the documentation.
It is understood Nantes are threatening legal action if they do not receive a payment within 10 days. BBC have attempted to speak to Nantes for a comment.
A source at Cardiff says they will honour the contract, but not until they have clarified "all the facts."
And Cardiff are "surprised" Nantes have made the demand while attempts are being made to recover a body from the plane wreck that was carrying Sala and pilot Ibbotson.
The body was seen in the Piper Malibu N264DB on Monday, two weeks after the plane vanished near Guernsey.
BBC Wales has learned the transfer fee is due to be paid in instalments over three years.
French club Bourdeaux are also entitled to a cut of the fee, thought to be 50 per cent after Sala was on their books from 2012-2015 before joining Nantes.
The plane carrying Sala, 28, and Ibbotson, from Crowle, Lincolnshire, disappeared on route to Cardiff on 21 January after the footballer returned to Nantes to say goodbye to his former teammates.
AmitOutstandingGar
174
sala and pilot family should be distributed the 15 million between them .it would be biggest consolation for both the family .RIP 😗
Ismitty
134
I can't believe this so all they care of is Money 💶 Can't they wait a little bit before they demand for Money at least wait until the plane and body is found I'm Suprised and disappointed with what Nantes want to do
Min_11
100
As a lover of football, This was my doubt from the day Sala went missing. Both the club are not so wealthy, so out of respect and sympathy they can share the losses 50-50. Its in the hands of Nantes coz cardiff can do nothing about it since the deal was signed. Cardiff city are the real victim, hopefully they recover the amount one way or the other. Lets wait n watch how much sympathy Nantes have for Cardiff. If they share the losses it will be a blessing for them
Tayaceinpz
63
At the end of the day it boils down to business 😔😔😔