diplomatic role in Moscow, and was one of the agents responsible for the retrieval of the valuable Mitrokhin Archive in 1992. From March 1992 until September 1993, he worked in the Eastern European Controllerate of MI6 under the staff designation of UKA/7. Whilst working there, it was discovered that the Conservative Party had been receiving donations from Serbian supporters. In November 1993, he joined the Balkans Controllerate, and was posted to Sarajevo for six months as the MI6 representative in Bosnia during the breakup of the former Yugoslavia. There he was a "targeting officer", with a mission to identify potential informants and gather intelligence. A soldier who escorted Tomlinson to Bosnia described him as a "liability", a "sulk" and "totally unprofessional", although Tomlinson has disputed this. From 1994 to 1995, Tomlinson worked in the operational counter-proliferation department. His first posting in this capacity was to work as an undercover agent against Iran, where he succeeded in penetrating the Iranian Intelligence Service. He posed as a British businessman, and infiltrated a network of arms dealers that included Nahum Manbar. The British government supplied the Iranians with materials for chemical weapons in order to gain intelligence on Iran's military programme. Tomlinson's description of his Iranian activities are generally considered to be true, due to his personal involvement and knowledge of details that only an insider would know. On 13 May 1994, Tomlinson resigned from MI6, suggesting in his letter of resignation that he had lost the motivation for a career with the organisation. He was later permitted to rescind his resignation. MI6 dismissed him on 22 May 1995 as he came to the end of his extended probationary period. Tomlinson's probationary period had been extended over the standard six-month duration due to his senior line manager's doubts about his personality. Tomlinson claimed that he had become suicidally depressed following the death of his long-term girlfriend from cancer and that he had been suffering from post-traumatic stress after witnessing violence against a civilian during the siege of Sarajevo, and that MI6 had been ill-equipped to handle his condition. MI6 argued that he was dismissed for "not being a team player, lacking motivation and having a short-term interest in the service", but later conceded that he had experienced a "personality clash" with his senior line manager. Another reason given for his dismissal was for "going on frolics on his own". Tomlinson claims that no