Cardiff City have been ordered to pay Nantes the first €6m (£5.3m) instalment of the transfer fee for Emiliano Sala, which is a defeat for the club’s argument that the contract to sign the player was not fully concluded at the time he died in a plane crash on 21 January.

Fifa’s players’ status committee, which determines disputes relating to international transfers, found against Cardiff and in favour of the French Ligue 1 club, for whom the 28-year-old Argentinian striker had been the top scorer before Cardiff signed him.

Nantes are expected to seek the two further annual instalments when they fall due, and the Fifa ruling means Cardiff are likely to be ordered to pay them.

Cardiff publicly announced Sala as their record signing on 19 January but after his death the club refused to pay Nantes the due first instalment, arguing that the contract had not been legally concluded. In an assertive response after Nantes took the case to Fifa Cardiff claimed the terms proposed in the contract breached Premier League rules governing signing-on fees and that four specific clauses still needed to be renegotiated and finalised.

Nantes, however, argued that all required paperwork had been completed and filed and that Fifa had registered the international transfer certificate for Sala at 5.30pm on 21 January.

The Piper Malibu light aircraft commissioned to fly Sala back to say his farewells at Nantes crashed on the return flight, at 8.16pm that night.

Last month investigators stated that Sala had potentially fatal levels of carbon monoxide in his blood and the pilot, Dave Ibbotson, 59, was likely to have been similarly exposed as the cockpit was not separate from the cabin. Ibbotson’s body has never been found.

Fifa said in a statement announcing the decision of its 24-person players’ status committee, which is chaired by a senior South African lawyer, Raymond Hack: “In a meeting held on 25 September 2019 the Fifa players’ status committee established that Cardiff City FC must pay FC Nantes the sum of €6,000,000, corresponding to the first instalment due in accordance with the transfer agreement concluded between the parties on 19 January 2019 for the transfer of the late Emiliano Sala from FC Nantes to Cardiff City FC.

“The Fifa players’ status committee, which never lost sight of the specific and unique circumstances of this tragic situation during its deliberations on the dispute at stake, refrained from imposing procedural costs on the parties.

“Within a deadline of 10 days Cardiff and Nantes can request a copy of the grounds of the decision, which can be appealed to the court of arbitration for sport in Lausanne.”

A spokesman for Cardiff said the club will be “seeking further clarification” from Fifa on the ruling “in order to make an informed decision on our next steps”.