A Uzbek politician jailed over 20 years ago on embezzlement charges that supporters say stemmed from his opposition to the late strongman Islam Karimov has been freed, a family friend told AFP on Thursday.

"Yes, he is free," said photographer and filmmaker Umida Akhmedov by email after speaking to Kukanov's son Sardor.

Kukanov's original 20-year-sentence was extended at least once during his term and a Tashkent-based rights group said it was extended for a further three years in October.

Kukanov's release comes as interim President Shavkat Mirziyoyev looks to consolidate control over the Central Asian country following the death in September of Karimov after 27 years at the helm.

Mirziyoyev served as Karimov's prime minister for 13 years.

Steve Swerdlow, a Central Asia researcher for the New York-based Human Rights Watch group told AFP the diplomatic community, including the US government, which publicly appealed to the Uzbek government to release him, had played an important role in securing Kukanov's release.

"If interim president Shavkat Mirziyoyev is serious about showing the world that his rule will be an improvement over Islam Karimov's repression he'll need to release many more political prisoners in addition to ending torture," Swerdlow added.

Uzbekistan was a serial human rights abuser under Karimov, who parlayed the country's strategic location on the Afghan border into geopolitical favour with Russia and the West.

The Muslim-majority country of 32 million people is Central Asia's most populous and rich in commodities including cotton, gold and gas.