Neymar must pay 6.7 million euros ($7.53m) to Barcelona, a court ordered on 19th of June after the player's case against his former employer was dismissed.
After his world-record transfer to Paris Saint-Germain in 2017 the Brazilian forward sued Barca for 43.6 million euros that he claimed he was due for various bonuses.
But a judge dismissed Neymar's case and instead sided with Barcelona, who had also sued their former player for breach of contract.
Neymar has five days to appeal the decision.
He joined Barca in 2013 and signed a new five-year contract in 2016, which included a renewal bonus worth 43.6 million euros, with 14 million paid up front.
The remaining 29 million euros was due to be paid on August 1, 2017 but Neymar left Barcelona on August 3 for Paris Saint-Germain, who activated the striker's 222 million euro release clause.
Barcelona refused to pay Neymar the remainder of the bonus, insisting the terms of his contract had been broken.
The club in turn sued Neymar and requested the return of the 14 million euros they had paid him up front, as well as a further 8.5 million euros in damages.
"We express our satisfaction with the verdict announced today," Barcelona said in a statement.
The ruling has fully dismissed the player's claim for payment of EUR43.6m, and has accepted a large part of the defence presented by FC Barcelona, as a result of which the player must return EUR6.7m to the club.
Source: https://www.france24.com/