Neymar joined the Catalan giants from Brazilian outfit Santos for £40million in 2013.
But Chelsea, City, Bayern Munich and Real Madrid were all chasing his signature prior to his big-money move.
And according to football outlet Goal, a Spanish judge has ordered the aforementioned clubs to submit documentation detailing the offers they made.
They claim DIS, a Brazilian company that owned a 40 per cent stake of Neymar's rights are still out of pocket from that transfer.
The report suggests the signing-on fee payment of £7m made by Barca two years before his move, flouted the free market rules for the transfers of players.
Barca, judge Jose de la Mata Amaya claims, committed fiscal fraud.
Neymar is currently on Copa America duty with Brazil.