Videotapes of rebel-held hostages were revealed on Friday by Colombian officials. Among the hostages there were three U.S. defense contractors and French-Colombian politician, Ingrid Betancourt.

These footages are the first evidence that the captives are alive.

According to High Commissioner for Peace, Luis Carlos Restrepo, the tapes were confiscated on Thursday after three suspected urban members of the Revolutionary Armed Forces of Colombia were arrested.

Officials also recovered a series of letters written by hostages, CBS News reports.

The videotapes were played at a news conference with no sound and it showed Ingrid Betancourt extremely thin, in a jungle background, looking at the ground. The recording was dated October 24, 2007. She was kidnapped in 2002, when she was in campaign for her presidency.

French President Nicolas Sarkozy said that he would redouble efforts to ensure her freedom.

He said: “I have always said we will never forget Ingrid Betancourt. We know she is alive. Now we have to fight with all our might to free her from her ordeal," BBC News quotes.

Betancourt's sister, Astrid Betancourt said: “It is a sad image, but she is alive. I am extremely moved to see these images of my sister.”

Other tapes showed the three Americans- Thomas Howes, Keith Stansell and Marc Gonsalves- also against a jungle background, looking weary. They were abducted in 2003 when surveillance plane went down in southern Colombia jungle. The three Americans were called by the U.S. embassy in Bogota the longest-held U.S. hostages currently in captivity.

This tape was dated January 1, 2007, but one Colombia soldier who also appeared on the same tape, said that it was made on October 23, 2007.

During the recent mediation effort of Venezuelan President Hugo Chavez to obtain the release of the 45 hostages held by FARC, the U.S., French and Colombian governments demanded “proof of life.”

FARC leaders offered to release the hostages in exchange of imprisoned rebels.

Astrid Betancourt says that the dates indicated the fact that the rebels intended to give the tapes as proof of life to Chavez.

Last week Colombian President Alvaro Uribe put an end to Chavez’s role of mediator on grounds that he exceeded his bounds when he contacted directly Colombia’s army chief.

On the five tapes there were also another 12 Colombians, mainly police and soldiers.

Among the letters that were found, one was written by Howes to his wife and another one was his will and was dated November 26, 2006. Another letter was written by Betancourt to her mother, dated October 24, 2007.

Due to Chavez’s dismissal, the two countries are in a diplomatic spat.

Uribe was asked by the families of the hostages to bring back Chavez into the process, because he was the best hope in years for their loved ones.

Uribe proposed military rescues of those kidnapped, but the families fear that he hostages will be killed in crossfire.