Barcelona said on Thursday that forward Neymar's legal representatives had paid his 222 million euros (200 million pounds) release clause and French television station RMC Sports said the Brazilian had signed a five-year contract with Paris St Germain.
Barcelona said in a statement on their website that his legal representatives "visited in person the club's offices and made the payment of 222 million euros in the player's name with regards to the unilateral termination of the contract that united both parties."
Barcelona said they would pass on details of the operation to European soccer body UEFA "so that they can determine the disciplinary responsibilities that may arise from this case."
UEFA, whose financial fair play rules ban clubs from spending more than their generated revenue, could not immediately be reached for comment.
A source from Spain's La Liga said earlier on Thursday that the league had rejected the payment of the clause after Neymar's lawyers visited its headquarters in Madrid to try to settle the transfer and pay the fee.
It was not immediately clear whether La Liga's refusal to accept payment would put the brakes on a transfer that mega-rich PSG believe will help them conquer the Champions League.
PSG's president Nasser al-Khelaifi declined to comment when asked about the latest development during a visit to a children's holiday camp outside Paris, where French President Emmanuel Macron was also in attendance.