La Liga has rejected an attempt by lawyers for Barcelona forward Neymar to pay his buyout clause of 222m euros (£200m), BBC report.
The Brazil international, 25, is set to sign for Paris St-Germain for a world record fee, after telling Barcelona he wanted to leave on Wednesday.
La Liga officials believe PSG are violating Uefa’s Financial Fair Play (FFP) rules.
But PSG do not think the issue will delay Neymar’s transfer.
A senior source at the Ligue 1 club told BBC Sport’s Richard Conway that La Liga was acting unlawfully, and that they are taking steps to resolve the situation.
The French league (LFP) says it is “surprised and does not understand” La Liga’s decision and has asked its Spanish counterpart “to abide by the Fifa rules and its responsibilities”.
A Barcelona spokesman told the Associated Press that they were “waiting to see how the situation develops”.
The club said previously that they would report PSG to Uefa, European football’s governing body, for a FFP breach.