Colombian officials released on Friday newly obtained videos of rebel-held hostages, among them three U.S. defense contractors and a former presidential candidate _ the first images in years providing evidence the captives may be alive.

The tapes were seized in the arrest Thursday evening in Bogota of three suspected urban members of the Revolutionary Armed Forces of Colombia, better known as the FARC, said Luis Carlos Restrepo, the government's peace commissioner.

This photo released by the Colombian government Friday, Nov. 30, 2007 shows former presidential candidate Ingrid Betancourt. Colombia's Peace Commissioner Luis Carlos Restrepo said that the photos and video tapes were confiscated after the arrest of three suspected members of the Revolutionary Armed Forces of Colombia, Thursday, Nov. 29, 2007.

Also recovered were a series of letters apparently written by the hostages, including what appeared to be the will of U.S. contractor Thomas Howes.

The videos of hostages held by Colombia's leading rebel group were made public immediately after their discovery, Restrepo said. They were apparently written and recorded as recently as late October.

The U.S., French and Colombian governments had demanded the so-called "proof of life" during Venezuelan President Hugo Chavez's recent ill-fated mediation effort to obtain the release of 45 high-profile hostages held by the FARC. But the FARC, by all accounts, never delivered the material to him.

The videotapes, which were played at a news conference without sound, showed an extremely gaunt Ingrid Betancourt, a dual French national seized while campaigning for president in 2002, apparently chained and in front of a jungle backdrop.

In the images, Betancourt has long hair and stares blankly at the ground. No images of her have been seen since 2003.

Betancourt has become a cause celebre in France and that country's president called the video "undeniable" evidence that Betancourt "is alive."

"This encourages us to boost our efforts to win her release," President Nicolas Sarkozy said.

"It is a sad image, but she is alive," Betancourt's sister, Astrid Betancourt, said on French television broadcaster LCI. "I am extremely moved to see these images of my sister."

The Colombian government said that the tapes carried the time stamp for Betancourt of Oct. 24, 2007. The tape of the Americans carried the date of the Jan. 1, 2007. But a kidnapped Colombia soldier, who appeared on the same tape, said the recording was being made on Oct. 23.

Astrid Betancourt said the October dates indicate the rebels had intended to give the footage to Chavez, who was pushing for proof of life at that time.