Lisbon - Rui Pinto, the hacker linked to the Football Leaks website, who is being held in Portugal awaiting trial, wants to continue aiding investigations in other European countries, his lawyers said on Monday.

Pinto, who is Portuguese, was involved with a series of leaks that exposed murky dealings across European football. He was extradited from Hungary to Portugal on March 21.

The Portuguese prosecutor has charged Pinto, who hacked millions of files, with "aggravated attempted extortion" and data theft. He could face 10 years in prison.

"Rui Pinto wants to collaborate to help advance the investigations," said French lawyer William Bourdon, at a conference on the protection of whistleblowers organised by Portuguese Socialist MEP Ana Gomes.

Pinto's Portuguese lawyer, Francisco Teixeira da Mota, said he spoke with his client on Monday morning.

"He is fine as far as is possible, he is in prison, but he wants to fight," said Teixeira da Mota."

The Portuguese authorities suspect Rui Pinto accessed the computer systems of the Portuguese state, Lisbon's Sporting football club and the investment fund Doyen Sports and then published confidential documents on a website created in late 2015.

The hacker then asked Doyen for money to hush up compromising documents, but he has said this was part of his attempt to show the dishonesty in football.

His lawyers say Pinto is a "very important European whistleblower" who made possible investigations in several countries into alleged malpractices in football.

"This is just the beginning of the story," Bourdon said, adding that Eurojust, the EU's Judicial Cooperation unit "has a copy of all that has been seized."

Belgian and French authorities "wish to meet Pinto again" said Bourdon adding that these meetings should take place in Portugal "within the framework of Eurojust mechanisms.

Gomes said Pinto could "provide valuable help in recovering money stolen through tax evasion."

In 2016, he handed four terabytes of data to a European media consortium, which uncovered tax evasion, possible fraud and corruption involving star players and club officials.

"I was working with the French authorities, starting a collaboration with Swiss authorities and probably about to start another European collaboration, and suddenly Portugal sabotaged everything," Rui Pinto said before his extradition.

"I have no confidence in the Portuguese authorities," he added.