Barcelona are suing Neymar for €8.5m (£7.8m) for alleged breach of contract and are demanding the return of a loyalty bonus as the fall out continues from his world record transfer to Paris St Germain.
The Brazilian forward signed a new five-year deal with Barcelona in 2016, but the club was powerless to stop his move to France just a year later because the French club met the buyout clause in his contract.
In a statement, Barcelona said: “In this lawsuit, the club demands the amount already paid as a bonus for the renewal of his contract for breach of contract, €8.5m in damages, and an additional 10% in interests.
“Barcelona have taken these actions in defence of their interests, after Neymar’s contract was rescinded just a few months after he signed on until 2021.”
The club said it had lodged the demand against Neymar on 11 August with Barcelona’s employment court, eight days after his move to Ligue 1.
The Catalan side has also passed the claim on to FIFA and the French Football Federation to take what it sees as “the appropriate legal effects”.
It comes two days after Neymar criticised Barcelona’s under-fire board after scoring twice in his home debut for PSG.
The French side beat Toulouse 6-2 on Sunday.
Neymar told reporters: “There are people in charge that shouldn’t be there. Barca deserves much more and everyone knows that.”
Barcelona has also withheld a €26m bonus due to the striker for signing the renewal to his contract last year.
Josep Vives, a spokesman for the club, said on 4 August: “The player hasn’t fulfilled his contract with the club… given that breach the club will not pay this renewal bonus.”
PSG signed Neymar for a world record €222m (£203m) earlier this month.