Viktor Bout, 41, was arrested in Bangkok on March 6 in a joint police operation led by the U.S. Washington is seeking Bout's extradition on charges of illegal weapons deals with militant groups, including the Taliban and al-Qaeda, in Middle East and African countries.
"As far as I know, some extradition trials in Thailand have lasted up to two years in the past, including appeals," Bout's Russian-based attorney, Yan Dasgupta, told a news conference at RIA Novosti.
Despite earlier reports, the Thai Foreign Ministry has not yet received an official extradition request from Washington and no extradition procedures have been launched.
"According to U.S. diplomats in Thailand, the extradition request has not been finalized and has not been passed on to Thai authorities," Dasgupta said.
Bangkok Criminal Court extended custody of Bout by 12 days on Wednesday. Although both Thai and U.S. authorities accuse Bout of supplying weapons to terrorist organizations, official charges against him have yet to be filed.
"We are having trouble in building up a solid argument against any possible charges since there have been no final charges presented to us", Dasgupta commented.
Bout is a former lieutenant in the Russian military who quit the armed forces in 1991. He then allegedly transformed himself into an international arms dealer, earning the nickname 'the Merchant of Death.' Western media invariably refers to Bout as a "former KGB officer."
Western law enforcement agencies consider him to be "the most prominent foreign businessman" involved in trafficking arms to UN-embargoed destinations.
Bout could face 15 years in prison on the U.S. charges, and 10 years on the Thai charges, if convicted.
Meanwhile, Bout's lawyer said on Thursday that the bank accounts of several companies linked to his client had been arrested, although he refused to provide any details.
U.S. authorities took measures against Bout in 2005, freezing his bank accounts and submitting a list of 30 companies linked to Bout to the UN Security Council Sanctions Committee.
Bout's lawyer also reiterated his client's claims that he has never been involved in criminal activities in Thailand, the U.S., or Russia.
"As far as Russia is concerned, he [Bout] has always been a law-abiding citizen, and does not face criminal prosecution in the country," Dasgupta said, adding that there were no legal grounds for requesting Bout's extradition to Russia.
He also said Belgium had lifted criminal charges against his client. Earlier reports quoted a source at Interpol's Russian Bureau as saying that Bout had been placed on Interpol's wanted list on Belgium's initiative.