Earlier Colombian officials had said that Lizcano was was rescued in a "joint intelligence operation" by the police and army in the region on the border with Panama.

Martha de Lizcano, his wife, said that the operation had brought to end "eight years of great suffering".

Lizcano was seized in Caldas province on August 5, 2000.

At the military base in Cali, Lizcano apologised for his somewhat incoherent speech and thanked "the person who had the courage, the valour to leave with me".

"I was really sick," he said before being taken for medical checks.

Later, Alvaro Uribe, Colombia's president, said that the deserter, who is known only by his alias "Isaias" or "Isaza" would be rewarded for helping Lizcano escape.

Deserters

Luis Carlos Restrepo, the government's peace commissioner, said last week that Farc deserters had reported Lizcano's health was delicate.

Farc had hoped to swap Lizcano for members of the group in Colombian jails [File: EPA]
Juan Manuel Santos, the defence minister, said on Sunday that a member of the group holding Lizcano had escaped in early October and provided details about his camp.

Troops and police had cordoned off the area around the camp after they began a rescue operation over the weekend, he said.

The former politician was one of a group of 29 high-profile abductees, including three politicians and 26 security personnel, that the Farc wanted to swap for about 500 of their colleagues who are in prison.

"There are so many more people who are still left in the jungle. We have got to get them all out. Not one can remain kidnapped. It is inhumane," she said.

The escape follows the rescue of Ingrid Betancourt, a former presidential candidate, three Americans and several other hostages, in July.

Farc has been fighting government forces in the Latin American country since the 1960s, but isa believed to have been seriously weakened by a security operation launced by Alvaro Uribe, the Colombian president.

Three Farc commanders have been killed during the past year and hundreds of fighters are reported to have deserted. Howver, scores of hostages are still being held by the group

Uribe has received billions of dollars in US military and counter-narcotics assistance to tackle Farc and the cocaine trade that has helped fuel the conflict.