Trading on his alleged service as a major in the Uzbek National Security Service (SNB), Yakubov claimed he was privy to information that indicted the Uzbek government on a variety of incendiary charges.
The refugee said he had evidence of Uzbek president Islam Karimov's direct culpability for the 2005 Andijon massacre; he charged the Uzbek government with undertaking a number of acts of "false flag" terrorism as pretexts to crack down on political opponents; and he accused the government of engineering a 2004 plane crash in Tashkent that killed UN envoy Richard Conroy.
RFE/RL reported on his allegations in 2008 after a lengthy interview with Yakubov. The BBC's Peter Marshall also conducted an interview with Yakubov in 2009 for the television news program "Newsnight."
But Yakubov's credibility has come under intense critical scrutiny in the aftermath of his recent conviction by a UK court for using a forged Portuguese driver's license that he claimed to have earned while on assignment for the SNB.
Yakubov has claimed that if he is deported back to Uzbekistan, he will face the violent retribution of the Uzbek government.
But a widely-known Uzbek human rights advocate, Surat Ikramov, has told RFE/RL's Uzbek Service in an interview that Yakubov is not quite who he claims to be, and suggests that Yakubov's personal safety would not be in danger should he be deported back home.
"Whatever he is claiming is information he picked up while working for my organization," Ikramov said.
No Access To State Secrets
Ikramov is the head of the Independent Human Rights Defenders of Uzbekistan, and no friend of the Karimov regime.
Human Rights Watch has called Ikramov "a fearless critic of the Uzbek government." Ikramov's activities have put him in personal peril: in 2003, the rights advocate was kidnapped, beaten, and abandoned on a riverbank outside Tashkent under mysterious cirumstances.
The story that Ikramov told of Yakubov's career and flight to London differs significantly from Yakubov's account.
Ikramov claimed that before Yakubov came to work for his human rights group "as an ordinary translator," he had been fired from a low-level government post inside the Uzbek security council, a position that would not have given Yakubov access to sensitive information.
"People like him would not have access to any state secrets," Ikramov said.
Ikramov said that Yakubov was suffering from a spate of personal setbacks, including the loss of his government position and a divorce that left him without his wife and two children.
In 2008, Ikramov brought Yakubov as a translator to a human rights conference in London. When they were there, Ikramov says, Yakubov asked for permission to stay in the UK for an extra week "to study."
Shortly thereafter, Yakubov claimed political asylum. "These days, he's cut all relations with me," Ikramov said.
'No Danger' To Yakubov In Uzbekistan
Ikramov noted that Yakubov's accusations against the government barely registered in Uzbekistan.
"Here in this country, there was no reaction at all to any of his claims." Ikramov said. "If there had been any reaction, I would think he might be in danger."
Ikramov maintains that he was "very surprised" not to have heard any significant reactions from Uzbek government officials regarding Yakubov's allegations.
"After all his claims, no one called me or summoned me even though he worked for me for a year," Ikramov said.
Cautioning that it is only his "personal opinion," and noting that the Uzbek government's behavior is "unpredictable," Ikramov concluded that Yakubov faces "no danger" in returning to Uzbekistan.
"I believe if he's sent back, no one will pay attention to him," Ikramov said.
-- Charles Dameron with reporting from RFE/RL's Uzbek Service