Barcelona are seeking at least 8.5 million euros ($10 million) from Neymar for breach of contract, the club said on Tuesday as the bitter fallout rumbles on from his world record 222-million-euro move to Paris Saint-Germain.
"In this lawsuit, the club demands the amount already paid as a bonus for the renewal of his contract for breach of contract, 8.5 million euros in damages, and an additional 10 percent in interests," Barcelona said in a statement.
Neymar signed a new five-year deal with Barca in 2016, but the Catalans were powerless to stop his move to PSG just a year later as the French side met the buyout clause in his contract.
Barca added the demand was lodged against Neymar on August 11 with Barcelona's employment court, eight days after his stunning move to Ligue 1.
The Catalan giants have also passed the claim onto FIFA and the French Football Federation via the Spanish Football Federation to take what they see as "the appropriate legal effects".
Moreover, Barca urged PSG to pay the amount they are seeking if Neymar -- who is reported to earn 30 million euros after tax for the next five years in Paris -- isn't able to meet their demands.
The club's latest move comes two days after Neymar fiercely criticised Barcelona's under-fire board after scoring twice in a stunning home debut as PSG beat Toulouse 6-2 on Sunday.
"There are people in charge that shouldn't be there," Neymar told reporters.
"Barca deserve much more and everyone knows that."
Barcelona have also withheld a 26 million euro bonus due to Neymar for signing the renewal to his contract last year.
"The player hasn't fulfilled his contract with the club...given that breach the club will not pay this renewal bonus," Barcelona spokesman Josep Vives said on August 4.