Abdugani Kamaliyev, 49, was put on a plane Wednesday in the central city of Tyumen and flown to the Uzbek capital, Tashkent, said Yelena Ryabinina of the rights organization Civic Assistance. He was sent to Uzbekistan despite a request from the Strasbourg-based European Court of Human Rights not to extradite him without a court hearing, she said.
"This is a demonstrative disregard of Russia's international commitments," she said.
She called the charges against Kamaliyev trumped up, and expressed fear that he will be subjected to torture and may not receive a fair trial.
The Tyumen prosecutor's office confirmed that Kamaliyev, who was arrested on Nov. 23, had been deported and said it was considering a complaint from Civic Assistance over the legality of his extradition. It gave no further comment.
Ryabinina said Kamaliyev was the second person in just over a year extradited by Russia to Uzbekistan in defiance of a ruling by the European human rights court.
Kamaliyev's expulsion, she said, was one of several cases where Russian authorities have stripped people of their citizenship to allow their extradition, circumventing the constitutional ban on the extradition of citizens.
Kamaliyev fled his native Uzbekistan in 1997 as President Islam Karimov launched a crackdown on the practice of Islam outside state-controlled institutions under the pretext of fighting extremism. Thousands of people have been jailed since, facing allegation of extremism, human rights groups say.
Karimov's government is regarded as one of the most repressive in former Soviet Central Asia, and has long been criticized internationally for using torture in prisons and jails.
Uzbek authorities had been seeking Kamaliyev since 1999 on charges of religious extremism, Ryabinina said. Kamaliyev became a Russian citizen and received a passport in 2000.
Six years later, though, he was detained in Tyumen, a city about 1,700 kilometers (1,000 miles) east of Moscow, at the request of Uzbek authorities. He was released several months later.
Authorities later accused Kamaliyev of getting his passport illegally, Ryabinina said.
Svetlana Gannushkina, who heads Civic Assistance, said that Russian officials appear to pay little attention to the constitution when it comes to extradition requests from friendly autocratic regimes in oil- and natural gas-rich Central Asia.
"A human being and his rights mean nothing in this country if we can oblige our friends," she said.
Britain sought the extradition of Alexander Lugovoi, identified as a suspect in the radiation poisoning death of Alexander Litvinenko, in July. Russian authorities refused, citing the constitutional ban on the extradition of citizens.
After the May 2005 uprising in Uzbekistan's eastern city of Andijan, Russian authorities detained dozens of Uzbeks who had fled to Russia and handed them over to Uzbek officials, both openly and secretly, rights groups said.
During those protests, rights groups and witnesses say, Uzbek government troops killed at least 700 people. The government insisted 187 died and blamed Islamic militants for instigating the violence.
Ryabinina said at least six Uzbek men have been abducted by the Russian security service and secretly handed over to Uzbekistan over the past few years, later resurfacing in Uzbek jails.