Prosecutors in Portugal have denounced him as a criminal hacker, but his supporters describe the man behind the "Luanda Leaks" revelations as a public interest whistleblower.

Rui Pinto, the Portuguese self-taught hacker already tied to the "Football Leaks", has now come forward as the source of the spectacular "Luanda Leaks" revelations.

The stories based on his latest massive leak have already led to Angolan prosecutors filing fraud charges against Isabel dos Santos, the billionaire daughter of Angola's ex-president.

But Pinto himself, while described by supporters as a crusading whistleblower, faces trial in Portugal over the hacking operation that led to the "Football Leaks" scandal.

Pinto was arrested a year ago in Hungary and extradited to Portugal over the "Football Leaks" operation, which exposed details of the financial dealings and transfers involving clubs in Europe's top leagues.

His lawyers insist he is a "very important European whistleblower".

They point out that the millions of documents in his 2016 "Football Leaks" package exposed tax evasion, fraud and corruption to a consortium of European outlets.

Pinto said he leaked the documents on Isabel dos Santos out of "civic duty"
Pinto said he leaked the documents on Isabel dos Santos out of "civic duty" AFP / FERENC ISZA

And Pinto said he leaked the "Luanda Leaks" files -- drawn from 715,000 documents -- out of civic duty, asking for nothing in return.

Born in the northern suburb of Porto Vila Nova de Gaia, Pinto was mostly self-taught in computing, having never received advanced education in the field.

When he was 23, he allegedly hacked a bank based in the Cayman Islands, stealing 300,000 euros (330,000 dollars).

Although he denies wrongdoing, Pinto admits to having taken data that shows "how the Cayman Islands are largely used for tax evasion and to launder money".

Pinto discovered Budapest when he was an Erasmus student reading history. While he did not actually graduate, he decided to stay on in Hungary earning some money by helping out in his father's antiques business.

Pinto's lawyers argue he is a whistleblower who acted in the public interest
Pinto's lawyers argue he is a whistleblower who acted in the public interest AFP / FERENC ISZA

When Hungarian police arrested Pinto in Budapest last January, the warrant accused him of having hacked into the systems of the investment fund Doyen Sports.

Portuguese prosecutors say he tried to blackmail the company, demanding between 500,000 euros and one million euros, in return for not publishing information he had taken.

The hacker admits contacting the investment fund, but "only to confirm that they have done wrong" and to know "how much they were willing to pay" to avoid the publication of new documents.

A fan of FC Porto and Cristiano Ronaldo, Pinto said that he wanted to reveal "the principal protagonists in the dishonest football industry".

Immediately after his arrest, Pinto's lawyers said that he was "in love with football and disgusted by the activities he has progressively become aware of".

The spikey-haired hacker, described by relatives as "sociable and joyful", has been charged with 90 offences.

A Portuguese confirmed his case would go to trial earlier this month.

Pinto has accused the authorities of trying to silence him to stop him from cooperating with other European countries.

His supporters point to the impact his hacking has already had.

Several countries, including Britain, Belgium, France and Switzerland have already opened criminal investigations based on the "Football Leaks" documents.

The latest hard drive Pinto handed over to the Platform to Protect Whistleblowers in Africa (PPLAAF) provided the source material for the so-called Luanda Leaks scandal, say his lawyers.

Dos Santos, Africa's richest woman, is accused of syphoning off hundreds of millions of dollars of public money.