By LIBARDO CARDONA

He dealt a major blow from within to Colombia's leftist rebels, killing a member of the FARC's ruling junta with a shot to the head and toting the man's severed hand out of the jungle as proof.

Nearly a year later, the guerrilla turncoat known as "Rojas" says the government has double-crossed him.

He's stewing in jail while prosecutors investigate him for terrorism, theft, and murder, and he may never see a penny of his $320,000 reward, which was frozen to offer eventual indemnity to victims of four kidnappings attributed to him.

"With this kind of treatment for a deserter, what guerrilla is going to turn himself in?" Rojas told The Associated Press in a prison interview this week.

The rebel known as Pedro Pablo Montoya has been a headache for Colombian officials who offered hefty rewards to anyone who helps capture a senior guerrilla commander. The government didn't specify whether killers could get the award.

And Rojas, among their most famous deserters, is unrepentant. He is refusing to confess any crimes he may have committed during his 16 years in a rebel army that finances its operations with kidnapping and drug trafficking.

Prosecutor Mariano Ospina told the AP that Rojas is eligible for a reduced sentence of no more than eight years in prison under a 2005 law designed to encourage members of Colombia's far-right militias to demobilize.

But only if he confesses.

Rojas says he should never have spent a day in jail, because he surrendered believing he would get amnesty. "I didn't just kill a rank-and-file rebel," he notes.

He refused to tell the AP any details about his killing of Rios, or any other crime he allegedly committed.

Rojas spent 16 of his 33 years in the Western Hemisphere's last standing rebel army, his final months in the security detail of Ivan Rios, one of seven members of the FARC's Secretariat.

Late one night in March 2008, he killed Rios and the comandante's girlfriend in their sleep with close-range shots to the head. He cut off Rios' right hand as proof and carried it packed in ice as he surrendered to the army.

Colombia's government triumphantly presented Rojas at a news conference as evidence that the FARC was imploding.

Officials were clearly uncomfortable, however, about endorsing murder, and President Alvaro Uribe said "a government of laws can't encourage massacres."

The effort by Colombia's U.S.-backed armed forces' to decapitate the FARC was clearly aided by the program offering a total of $100 million in rewards. Less than a week before Rios' death, Colombia's military killed another Secretariat member, Raul Reyes, in a cross-border raid into Ecuador. The leaders' deaths contributed to more than 3,000 desertions last year, according to the Defense Ministry.

Rojas' reward money was banked in his name but frozen by prosecutors, who "say it's for reparations to my victims," the steely eyed guerrilla complained during the interview in La Picota prison, where he wore a bulletproof vest and was flanked by six guards.