TV contestant slain after confession

• A reality show contestant is found slain more than two months after she appears on TV
• Authorities accuse her ex-boyfriend of killing her over prize money
• Investigators are looking into what role the show played, Peru's attorney general says
• Host: Critics of the show "are giving an alibi to a soulless criminal"

(CNN) -- A Peruvian reality show has become part of a real-life crime drama as authorities investigate the slaying of a contestant who appeared on the program.

Ruth Thalia Sayas Sanchez's body was found in a shallow grave Saturday, more than two months after the 19-year-old's on-air confession that she worked in a nightclub and twice accepted money for sex.

Investigators found evidence of poison in her body, Peruvian Attorney General Jose Pelaez told reporters.

Authorities accuse her ex-boyfriend of killing her because he felt he was entitled to some of the 15,000 soles ($5,700) she won on the show, according to police accounts reported by local media.

Sayas was the first contestant on "The Value of Truth," which features participants answering tough questions about their personal lives in front of an audience and loved ones. Before appearing on the show, contestants are subjected to a polygraph test to verify their responses.

Pelaez said investigators were looking into the role the show could have played in Sayas' death.

"The investigation will determine whether there is some degree of responsibility, even though it seems to me that it would be a responsibility that would not have a causal relation," he told reporters.

Facing increased scrutiny, the show's host has said the program is not responsible for her slaying.

Criticism of the show is unfair, host Beto Ortiz said.

"What they are doing is giving an alibi to the defenders of a soulless criminal, because they are taking away his responsibility by saying that television creates monsters," he said.