Ana Belen Montes, a former US defence intelligence analyst convicted of spying for Cuba, was released from a federal prison in Texas after spending more than 20 years behind the bars.

According to the Federal Bureau of Prisons website, Montes was released on Friday.

Montes, 65, was arrested in 2001 and was accused of using her position as a Defense Intelligence Agency (DIA) official to supply information, including the identities of US spies to Havana.

In 2002, Montes pleaded guilty to conspiring to commit espionage and received a 25-year prison sentence.

Montes to remain under supervision

Ricardo Urbina, the sentencing judge, ordered that Montes be placed under five years of supervision following her release with her internet usage to be monitored. Montes has also been barred from joining government agencies.

Montes joined the DIA in 1985 and rose up its rank to become the organization's top Cuba analyst.

The sensitive information leaked by Montes included revealing the identities of four undercover US agents to Cuba.

Some of the information leaked by her to Cuba was described by US prosecutors as being too sensitive to be revealed to the public.

According to court records, she also leaked details of US surveillance of Cuban weapons.

Urbina had said that Montes put fellow US citizens and the "nation as a whole" at risk.

mf/kb (AP, Reuters)