A deserter from Colombia's rebel Farc group is travelling to asylum in France with former hostage Ingrid Betancourt.
The ex-rebel, Wilson Bueno Largo, fled a Farc camp in October with one of the group's high-profile hostages, politician Oscar Tulio Lizcano, BBC reported.
Mr Bueno has been offered a new life in France and a reward of more than $400,000 (£270,000).
Ms Betancourt, a former Colombian presidential candidate, was rescued from the Farc earlier this year.
She was a hostage of the Revolutionary Armed Forces of Colombia (or Farc) for about six years until her dramatic rescue by the Colombian military in July.
She has been on a tour of Latin America, keeping the issue of Farc hostages in the public eye.
In October, Mr Bueno fled the Farc carrying Mr Lizcano on his back. The defection struck a massive blow to the morale of the rebel group, says the BBC's Jeremy McDermott in Medellin.
Mr Bueno, also known as Isaza, was a Farc veteran who had risen through the ranks to a command position.
Mr Lizcano had been held by Farc for eight years.
Colombian Defence Minister Juan Manuel Santos said Mr Bueno was being rewarded for the good acts he had committed, not the bad ones.
"It is extremely clear that we are not rewarding a kidnapping, but a brave attitude of somebody who did not agree with the kidnapping of Mr Lizcano and who facilitated, from his position inside the Farc, his release," said the minister.
The rebels now hold about 28 high-profile hostages - prisoners they hope to swap for Farc members held by the government.
Last year, France offered asylum to Farc rebels who defected as part of efforts to secure the release of hostages.
Farc has suffered a series of blows this year, including the rescue of several hostages and a number of high-level desertions.
Mr Bueno was just one of about 2,000 Farc members to desert this year, says our correspondent.