Cardiff City have accused Nantes of breaking Fifa rules over the tragic transfer of Emiliano Sala in their feud over his £15 million fee.

The Daily Telegraph can disclose details of the case Cardiff submitted to football’s world governing body on Monday to explain their withholding of the first instalment of the fee for the striker, who was killed in a plane crash almost three months ago.

As previously revealed by the Telegraph, the Premier League club told Fifa the deal they struck to buy the striker became “null and void” after he died because he signed a contract deemed non-compliant with Premier League rules and legally-binding clauses in their transfer agreement with Nantes had not been fulfilled.

But a source with knowledge of Cardiff’s submission confirmed yesterday it also accused Nantes of failing to disclose to Fifa’s Transfer Matching System that the agent Mark McKay had been acting for them in the deal.

Annexe 3 of the governing body’s Regulations on the Status and Transfer of Players (RSTP) states clubs must input the “club intermediary’s name and commission” into its TMS.