An Iranian official has called for the immediate release of former Iranian Ambassador to Jordan Nasrollah Tajik, who was arrested in Britain in 2006 over alleged involvement in nuclear deals.

“Considering the principles of human rights… Mr. Tajik should be freed as soon as possible, particularly given Washington's pressure for Tajik's extradition [to the US] without providing any proof or evidence [against him],” Hassan Qashqavi, Deputy Foreign Minister for Consular, Parliamentary and Iranian Affairs, told Fars news agency on Wednesday.

Tajik was arrested in the UK in 2006. He was accused of involvement in nuclear deals in violation of US sanctions on the Islamic Republic. The United States is pressuring British officials for Tajik's extradition.

Qashqavi pointed out that he earlier paid a visit to London, at the head of a delegation, to follow up on Tajik's case.

“In several meetings with Mr. Tajik and his lawyers, we found out that he is in appalling physical conditions,” he said.

Qashqavi added that a number of British doctors and psychiatrists have sent medical reports on Tajik's critical health conditions to Britain's Home Office.

According to the Iranian official, all the reports verified that the former Iranian envoy is suffering from different diseases and that his well-being is badly undermined.

Qashqavi went on to say that Tajik's mental health was also in danger as he had been under house arrest for nearly five years.

The Islamic Republic has rejected allegations against Tajik and called for his immediate release.

Iran's Foreign Ministry has been engaged in tireless diplomatic efforts to secure the release of the Iranian nationals held captive in other countries.