The Ecuador government has appealed for WikiLeaks founder Julian Assange to be given "safe passage" out of its London embassy for a few hours to undergo an MRI scan on his shoulder.
The Foreign Ministry cited a doctor's note that said Assange, who has been living at the address for over three years, is in "constant pain".
Details of the request to the Foreign Office - which was sent in late September and was rejected - emerged a few days after Scotland Yard removed a 24 hour police guard from the building.
Assange faces arrest if he leaves the embassy. He is seeking to avoid being extradited to Sweden where he faces a sex allegation, which he denies.
Ecuadorian foreign minister Ricardo Patino read out a letter from Assange's UK doctor, who examined the Australian in August, at a press conference.
Ecuador wrote to the Foreign and Commonwealth Office on September 30 to request that Assange be permitted to go to hospital.
Officials said hospital equipment required to scan Assange's shoulder cannot be brought into the embassy due to its size and weight.
Assange's US lawyer criticised the Foreign Office for "forcing him to choose between the human right to asylum and the human right to medical treatment".