The 62-year-old Mavlonov was one of more than two dozen human rights activists who had criminal charges brought against them in the aftermath of the bloody crackdown against protesters in the eastern Uzbek city of Andijon in May 2005, when security forces shot dead hundreds of demonstrators.
He was convicted of corruption and abuse of office. Mavlonov, a member of the Erk opposition party, said the charges were trumped up.
But he and four other activists -- Saidjahon Zainabitdinov, Dilmurod Muhitdinov, Ikhtior Hamraev, and Bahodir Mukhtarov -- were freed from prison on February 2-4.
The surprise release came on the eve of a key meeting in Tashkent between European Union and Uzbek officials on February 5.
Just Window Dressing?
Umida Niyazova, who was serving a suspended prison term, was also amnestied on February 3. Niyazova links her amnesty with international pressure put on the Uzbek government and a current "thaw" in relations between Uzbekistan and the West.
"I was amnestied, although a month earlier I received a formal refusal" from the authorities, she says. "Therefore I am absolutely positive that there is a direct link between my amnesty and international relations."
But other activists are skeptical about the releases, saying they are merely window dressing and that they don't signal any true change in the Uzbek government's abysmal human rights policy.
Dadakhon Hasan is a dissident singer and poet who was given a three-year suspended sentence in 2006 for writing and performing a song about the events in Andijon. He says the release of other prisoners that Uzbek President Islam Karimov considers his "enemies" is highly unlikely.
"They will not release those who they consider dangerous [for the regime]. Many are set free after they beg [Karimov's] pardon," Hasan says. "Others refuse to ask for a pardon. Their release is out of sight in my opinion."
The EU welcomed the move to release the prisoners. It also noted that a number of other human rights defenders are still jailed in Uzbekistan and it called for their immediate release.
Human Rights Watch (HRW) also called for the further release of more than a dozen activists. Veronika Szente Goldston, HRW's advocacy director for Europe and Central Asia, says the release of the six rights activists is "extremely significant" and demonstrates that sustained international pressure on Tashkent works.
International Pressure Working?
"These releases show that international pressure sustained over time on the Uzbek government can be effective in securing concrete progress in human rights," Goldston says. "This proves that the sanctions policy that the EU has in place has the potential to trigger positive change."
Goldston points out that more than a dozen other rights activists remain behind bars and "there is more that needs to be done." She continues: "These are significant initial steps that really show that the sanctions work as an effective leverage on the Uzbek government and it sends a message that the EU needs to maintain pressure and secure the release of all the other prisoners who are behind bars on account of their human rights work."
Goldston says the EU should maintain the pressure on Tashkent and "not give away the leverage prematurely."
Some observers believe the arrest on February 19 of Deputy Prosecutor-General Anvar Nabiev -- who was responsible for the prosecution of many of those imprisoned after the Andijon events -- is also connected to EU pressure.
The release of the jailed activists is one of the EU's demands outlined in a declaration adopted by EU foreign ministers in October 2007.
The EU came under fire after it suspended a visa ban on top Uzbek officials in October. Uzbek and international human rights groups accused Brussels of being "too soft" and also putting energy and geopolitical interests ahead of human rights and democracy.
The EU imposed the visa ban and a weapons embargo on Uzbekistan in October 2005 in response to the bloodshed at Andijon. The suspension of the visa ban came with a list of tough conditions attached to it.
Among the conditions the Uzbek government has yet to meet are full access by international bodies to the remaining prisoners, access to Uzbekistan for UN special rapporteurs, and the ability of nongovernmental organizations -- including HRW -- to operate freely in the country.
The International Committee of the Red Cross (ICRC) has been trying to get access to Uzbek prisons for years. The committee's representative -- who spoke to RFE/RL on the condition of anonymity -- said the ICRC has been engaged in negotiations with the Uzbek government but has not yet received access to the prisons.
There is speculation that the EU will not reinstate the visa ban when EU foreign ministers review it in late April, despite the Uzbek government's failure to meet most of the conditions needed for the ban to be waived.
Meanwhile, the European Parliament adopted its own initiative report on an EU strategy for Central Asia on February 20. The report noted "the slowness of implementation" of the EU's 2007 strategy for Central Asia. Members of the European Parliament also called on the European Council and the European Commission to "ensure that human rights issues should carry equal weight with the EU's robust approach to energy, security, and trade."
(RFE/RL's Uzbek Service contributed to this report.)