MADRID: The celebrated and controversial Spanish human rights investigator Baltasar Garzon is to lead the defence of WikiLeaks founder Julian Assange as he fights extradition from Britain to Sweden where he is wanted for questioning over rape allegations.

Garzon, who was disbarred as a judge in Spain in February, said he would lend Assange the weight of his knowledge of international human rights and extradition law in a case that he denounced on Wednesday as “arbitrary and baseless”.

He travelled to London to meet Assange, who has sought refuge in the embassy of Ecuador.

Garzon, who was the investigating magistrate when the former Chilean dictator Augusto Pinochet was arrested in London on an extradition warrant to face genocide charges in Spain, said he believed Assange to be the victim of obscure international political manoeuvring.

“There is clear political intentionality behind this affair, which explains his current situation,” said Garzon on Wednesday.

“Obviously this is not just about his future but his physical and psychological stability and it is only right that Mr Assange should be protected by the same rights as those of any other citizen.

Garzon added: “Assange has not rebelled against any jurisdiction, given that he respects the action of the law, but he — and we — are seriously worried about what will happen to him because his situation is taking on a political use as a result of the great work done by his organisation when it comes to denouncing corruption.

“That cannot be the reason for a judicial process that appears, and which I believe we can show, is arbitrary and totally baseless,” Garzon said, according to the Cadena SER radio station.

“It does not seem right that a single person should be under such pressure from governments,” said Garzon, referring to both Sweden and Britain. “I believe that Assange ... is in a situation that is an attack on his human rights.”

A WikiLeaks communique quoted in Spanish by the Europa Press news agency stated: “The secret process against [Assange] in the United Sates is a clear threat that contaminates any other process, such as the one that motivates the extradition request for questioning in Sweden, which appears to be a simple instrument designed to attain that other aim.”

We were unable to obtain an English version of the communique.

Garzon will help the defence team try to prove “abuse of due process and the arbitrariness of the international financial system, which will show the full extent of the operation against Julian Assange”, the statement added.

The organisation also reportedly criticised Britain for failing to extract “credible guarantees” from Sweden and the US.

Garzon's career as an investigating magistrate in Madrid in effect came to an end in February when the supreme court disbarred him for wiretapping conversations between defence lawyers and their clients in a corruption investigation involving the Spanish prime minister Mariano Rajoy's People's party.

He was given an 11-year suspension as supporters claimed he was the victim of a conspiracy to bring down one of the world's best-known human rights investigators, who had successfully pursued henchmen working for Argentina's military juntas.

By arrangement with the Guardian