A prominent Basque separatist has been released from a Spanish prison after serving more than six years on terrorism charges for trying to resurrect the banned political wing of the armed group ETA.

Arnaldo Otegi, former leader of the outlawed Batasuna party, was greeted by dozens of supporters Tuesday on leaving the prison in the northern city of Logrono.

Prior to his imprisonment in 2009, Otegi was considered the political leader of the pro-Basque independence movement.

Batasuna was banned in 2003 on the grounds it was part of ETA, which killed 829 people in a near four-decade campaign for a Basque independence.

The court ruled that Otegi was trying to form a new Batasuna under ETA's orders.

ETA announced a permanent cease-fire in 2011 but has not disarmed.