Julian Assange today expressed "shock" after new documents revealed fresh details about the involvement of UK authorities in the long-running saga which has seen the WikiLeaks founder live inside the Ecuadorian embassy for the past three years.
He was granted political asylum after fighting extradition to Sweden where he faced sex allegations, which he has always denied.
He fears that if he goes to Sweden he will be taken to the United States for questioning over the activities of WikiLeaks.
Assange has offered to be interviewed inside the embassy in London but attempts to set up a meeting have foundered.
Emails obtained by Italian news magazine L'Espresso under the Freedom of Information Act showed that Britain's Crown Prosecution Service wrote to the Swedish authorities in 2011, saying it would "not be prudent" for them to interview Assange in the UK.
"Any attempt to interview him under strict Swedish law would invariably be fraught with problems," said one email, dated January 25 2011.
Another email dated January 13 2011 said: "Please do not think that the case is being dealt with as just another extradition request."
Assange said: "This is astonishing. I have been on the phone with my lawyers all morning and they are as shocked as I am."
L'Espresso said Britain rejected its FoI requests, but the Swedish authorities released 226 pages of documents.
The magazine said the files revealed that from the very beginning the CPS in London advised the Swedish prosecutors against an investigative strategy it said could have led to a quick closure of the preliminary investigation into the case.
The Metropolitan Police only recently removed a 24-hour guard on the Ecuadorian embassy which had cost an estimated £12 million.