The Brazil international striker was unveiled as a 57.1m euro signing at the Nou Camp last June but a confidentiality agreement prevented full details of the contract being revealed.
A hearing will now decide whether any wrongdoing took place after Barcelona club member Jordi Cases demanded a response from officials to his request for clarity over the high-profile transfer.
State prosecutors backed the legal challenge and called for a hearing, having decided that there was sufficient grounds to believe there could be a case of 'contractual simulation'.
They have also pointed to a sum of 40m euros, which was reportedly paid as part of the overall fee, to a company owned by Neymar's father.
On Monday, Spanish daily El Mundo said the final figure was nearer 95m euros, prompting Rosell to ask for the hearing to 'give evidence and clear his name'.
In a news conference later that day, he said: "There are two points I would like to make. The first is a reaffirmation that Neymar cost 57.1m euros, full stop.
"I am saying it for the umpteenth time and that's enough now. The second is a request, with all my respect for the judge in this case.
"Ask him to initiate proceedings and call me to testify, precisely so I can tell the judge anything he would like to hear because there is nothing to hide.
"Everything is absolutely legal and absolutely clean. Any confidentiality clause that existed was always because it was asked for by the other side."
Judge Pablo Ruz will now seek more information from Neymar, Santos and Barcelona before deciding at a later date whether Rosell will be called in person to give evidence.