Barcelona's complaint relates to Neymar signing a new contract through 2021 in October of past year, with the club hoping to recoup his "renewal premium" as well as €8.5m in damages and a further 10 per cent in arrears.
Spanish football club Barcelona is suing Brazil striker Neymar for the €8.5 million euro ($10 million) bonus it paid him for signing a contract he later broke to join French side Paris Saint-Germain (PSG) on a world-record transfer.
However, Neymar has clearly not forgotten his Barcelona roots.
But the Catalans are now seeking to reclaim this bonus after the "unilateral termination of the contract" which enabled Neymar to swap Barcelona for Paris.
Neymar starred from beginning to end on his home debut for Paris Saint-Germain, scoring twice in a 6-2 thumping of Toulouse in Ligue 1 on Sunday.
Should Neymar - if the courts rule in the club's favor - be unable to pay, Barcelona has demanded that Paris-Saint Germain be made responsible for the completion of the payment. The club also claims that PSG subsidise the amounts in the event that the player can not take responsibility.
Barcelona is also demanding 8.5 million Euros in damages as well as an additional 10 percent for the delayed payment.
The timing and force of Neymar's comments seemed unusual at the time, but they now make ideal sense in light of Barcelona's lawsuit.
"FC Barcelona has started these proceedings to protect its interests following Neymar's decision to buy out his contract just months after he signed an extension until 2021". "But with [the board], no".
"For me, they are not the people who should be there, for the direction of Barca", said Neymar.
"I spent four attractive years there and parted happy".
"To see my former teammates unhappy makes me sad also, because I have many friends [there]".