Football's world governing body Fifa has been advised to launch legal action against former president Sepp Blatter and former Uefa president Michel Platini to recover more than £1.5m.
Blatter, 83, approved the "disloyal payment" of two million Swiss francs (£1.54m) to Platini on 18 January 2011.
The money was transferred to Platini's bank account by Fifa two weeks later.
It was subsequently established there was no basis for the payment to be made and it should be considered "a gift".
Fifa's governance committee has unanimously approved the advice to reclaim the money as a matter of urgency, plus an additional resolution for Fifa to demand interest on the payment and additional disciplinary fines and costs.
It is understood legal proceedings are yet to be instigated but, given the strength of the advice given by one of its own departments, it is virtually inconceivable it will not happen.
In an exclusive interview with BBC Sport in July, Blatter said he was "an honest man" and had begun legal action against Fifa for the return of 60 personal watches.
Blatter's 17-year spell in charge of Fifa ended amid a corruption scandal in 2015 and he is serving a six-year ban from football.
He alleges that false information was spread in relation to money received by him after the 2014 World Cup.
Fifa said Blatter's views should be seen "against the background of his own conduct in office over a period of decades".
Blatter and Platini, 64, both deny any wrongdoing.