This article is more than 1 year old

This article is more than 1 year old

WikiLeaks has said it has uncovered a surveillance operation against Julian Assange at the Ecuadorian embassy and that images, documents and videos gathered have been offered for sale.

Spanish police were said to have mounted a sting operation against unnamed individuals in Madrid who offered the material for sale in what lawyers and colleagues of Assange said on Wednesday was an attempt at extortion.

Some of the material came from video cameras with a capacity to record audio and which had been installed last year, a press conference organised by WikiLeaks was told.

Revealed: Ecuador spent millions on spy operation for Julian Assange Read more

WikiLeaks said material including video, audio, copies of private legal documents and a medical report had turned up in Spain, where a group was said to have threatened to start publishing unless they were paid €3m (£2.6m).

The Guardian reported last year that Ecuador had bankrolled a multimillion-dollar surveillance operation to protect and support Assange at the embassy, employing an international security company and undercover agents to monitor his visitors, embassy staff and even the British police.

Kristinn Hrafnsson, the editor-in-chief of WikiLeaks, said he had met four individuals, one of whom he was told was a ringleader and who had prior convictions. There was a possibility that at least one was not a Spanish national, he added. The matter is now in the hands of an investigating Spanish magistrate, according to the whistleblowing website.

Hrafnsson said the surveillance at the embassy – which had led to Assange living a “Truman Show existence” – was part of an escalation designed to result in Assange being extradited to the US.

“If you connect the dots it’s easy to draw that picture,” said Hrafnsson, who was appearing with the barrister Jennifer Robinson and Fidel Narváez, a former consul of Ecuador in London.

It remained unclear whether Assange was planning to leave the embassy of his own accord at any point soon. His legal team said they would still need assurances from the UK government that Assange would not face onward extradition to the US.

WikiLeaks said the surveillance had constituted a total invasion of privacy, which had included recordings of Assange’s meetings with his lawyers and doctor.

Robinson, a lawyer at Doughty Street Chambers who has long advised Assange, described the surveillance as a severe breach of lawyer-client privilege, which had undermined the ability of his legal team to properly defend their client.

Revealed: Ecuador spent millions on spy operation for Julian Assange Read more

Copies of photos, videos and documents recovered from the alleged extortionists were projected on to a screen at the press conference. There was no immediate comment from Ecuadorian authorities or Spanish police.

In March last year, Ecuador cut off Assange’s internet connection, saying he had breached an agreement not to issue messages that might interfere with other states. In a statement, the government said his behaviour on social media “put at risk the good relations [Ecuador] maintains with the United Kingdom, with the other states of the European Union, and with other nations”.

Supporters of Assange gathered outside the embassy in central London last Friday after the organisation said its sources in Ecuador had revealed he could be removed from the building “within hours to days”.

Ecuador’s foreign ministry released a statement last week saying it “doesn’t comment on rumours, theories or conjectures that don’t have any documented backing”, but a senior Ecuadorian official said no decision had been made.

WikiLeaks believes Assange would be extradited to the US if he left the building and was arrested by the Metropolitan police on an outstanding warrant for failing to surrender to bail.

In his first year in office, Ecuador’s president, Lenín Moreno, called Assange a “hacker”, an “inherited problem” and a “stone in the shoe”.