Neymar has made a complaint to FIFA over an unpaid loyalty bonus worth €26m after he signed a new contract with Barcelona last year.
Sky Sports reporter Bryan Swanson has reported that FIFA are now investigating the Brazilian forward's claims. The investigation is separate to that of Barcelona's announcement that they are set to sue Neymar for €8.5m over an alleged breach of contract.
The Catalan club are refusing to pay the €26m which is owed to the player's father in early August following a contract renewal in 2016.
Barcelona spokesman Josep Vives claimed earlier this month that the club will continue to refuse to pay the bonus.
"The club will not pay the bonus to Neymar's father," he said, quoted by Sky Sports.
"There were three conditions: the player must not negotiate his departure from the club during the month before the bonus became payable, he must demonstrate his desire to fulfil his contract, and that we would not pay out the bonus before September 1, to ensure the transfer window was closed.
"Now that we know that none of these three conditions were met, we will not honour that bonus."
A FIFA spokesperson, meanwhile said: "As a general rule, and without prejudice to the right of any player or club to seek redress before a civil court for employment-related disputes, the decision-making bodies of FIFA would be competent unless the parties have explicitly agreed for such dispute to be decided by an independent arbitration tribunal."
PSG, in response to the accusations, claimed that they: "Received the Barcelona statement with surprise" and that "the club, like Neymar Jr., has strictly complied with all the laws and rules and can only regret the attitude of FC Barcelona".