Colombian rebels admitted on Friday they did not have a boy they had promised to release last week in a Venezuela-sponsored hand-over of hostages and accused the government of snatching him just as he was about to be freed.

Many in Colombia were on tenterhooks over the year-end holidays waiting for Marxist guerrillas to release the child named Emmanuel, who was born in captivity and is thought to be 3 or 4 years old.

But DNA test results announced by the attorney general showed he was already living under state foster care in Bogota after being turned over by the rebels in 2005.

The revelation damaged the credibility of the Revolutionary Armed Forces of Colombia, or FARC, which had promised to turn him and two other hostages over to Venezuela's left-wing president, Hugo Chavez.

The deal to release Emmanuel, his mother Clara Rojas, and a kidnapped lawmaker named Consuelo Gonzalez crumbled on Monday when the rebels accused the army of intensifying its operations in a jungle area where the hostages were to be handed over.

Colombia's conservative President Alvaro Uribe accused the FARC of lying and said it did not go through with the hostage release because Emmanuel had already been quietly handed over to child welfare authorities.

In a statement late on Friday, the FARC said it had turned the boy over to a Bogota family to keep him safe until his official release, and called Uribe the real child-snatcher.

"Uribe kidnapped Emmanuel with the miserable intention of sabotaging his hand-over," the FARC statement said.

The episode worsens prospects for more hostage talks even though the statement said the FARC still wants to release Rojas and Gonzalez.

The rebel group, funded by cocaine smuggling, says it is fighting for socialism. But even left-wing Colombian politicians say it has scant popular support.

INSECT-INFESTED CAMP

Emmanuel was born to Rojas and one of her guerrilla captors in an insect-infested jungle camp where hostages are poorly fed and often chained, according to former captives.

He is seen as a symbol of the young victims of Colombia's four-decade-old guerrilla war and became a national obsession this week when Uribe said he was mistreated by his captors before being turned over to foster care.

Emmanuel's name and other details of his life in guerrilla custody were revealed last year by a police officer who escaped the rebels after eight years in captivity, sometimes in the same camps as Rojas and her son.

"The FARC was playing games again and this time Chavez was taken in," said Michael Shifter, Colombia expert at the Inter-American Dialogue think tank in Washington.

"This reinforces the impression that most Colombians have that the FARC cannot be trusted," Shifter said. "I expect both sides will dig in their heels, which is not good in terms of any possible hostage exchange in the future."

The rebel army is holding about 750 hostages for ransom and political leverage. They include French-Colombian politician Ingrid Betancourt, who was captured in 2002 along with Rojas, and three American anti-drug contractors seized in 2003.

The FARC says it wants to exchange some of its high-profile hostages for jailed guerrillas, but Uribe has refused the FARC's demand that he pull troops out of a large rural area where armed rebels could enter to hand over the captives.