ALMATY (Reuters) - A man described by human rights activists as one of the longest-serving political prisoners in Uzbekistan was released on Thursday, a local human rights group said, after spending 22 years behind bars.


The surprise move came shortly before the presidential election on Dec. 4 and could boost the image of interim president Shavkat Mirziyoyev, who is running for a full term.


Samandar Kukanov, 72, a former parliamentary deputy, was sentenced to 20 years in prison in 1994 on embezzlement charges after becoming a vocal opponent of President Islam Karimov.


In 2014, his term was prolonged for two more years for a breach of prison rules.


Karimov died in September after ruling the Central Asian nation of 32 million people with an iron fist for almost 27 years.


Kukanov's relatives had expected his release last month, but were instead informed he had been sentenced to three more years for violating prison regulations.

On Wednesday, however, Kukanov was unexpectedly released, according to rights group Ezgulik, which had contacted his family. The family and the authorities could not be reached independently for comment.

Prime Minister Mirziyoyev, who is widely expected to win the upcoming election, has amnestied several less prominent political prisoners. But analysts expect no significant changes in Uzbekistan's restrictive political environment.

(Reporting by Olzhas Auyezov; Editing by Tom Heneghan)