The gory murder of a woman and a boy took a new twist yesterday with police first saying that both victims were foreigners and killed over a Bt10-millon($0.419million) debt, and later revealing that a Thai man had confessed last night to killing both in "jealous rage".

The suspect, Siriphong Kanjananiwit, made his first confession in front of a group of reporters from the Thai News Agency (TNA), who were covering the case, by handing them a pistol and claiming he was responsible for the killings.

Police later went to the TNA office and escorted Siriphong to the Taling Chan Police Station, in whose jurisdiction the two bodies were found.

The suspect set some conditions for his surrender: he did not want to be handcuffed and that nobody but police officers should accompany him to a flat in Bang Bua Thong area in Nonthaburi.

He did not explain the reasons behind his demands.

Metropolitan Police chief Lt-General Worapong Chewpreecha, who also interrogated Siriphong, said the man's claims were not believable and the case would need further investigation.

Earlier yesterday, police said both victims were Koreans who might have been killed by compatriots over a Bt10-million gambling debt. Some news reports claimed that the woman had fled South Korea due to cases of alleged fraud.

The woman was identified as a South Korean called Lee Kwang-choo and the boy as Lee Jee-hun.

Citing an informant, police had earlier said the boy - who was shot, decapitated and mutilated - also had a younger brother called David, and both boys studied at an international school in Bang Na.

Quoting Siriphong, police said he had shot the woman, who was later identified as a Thai national named Sunant Srisuwan, in a jealous rage and quoted the suspect as saying: "I did not mean to kill the boy."

Siriphong reportedly said he was in tears while mutilating the boy's body, but did not say where he had discarded the three garbage bags holding the body parts.

He also said he did not know why the bags holding the boy's body parts had been found in an abandoned house in Bangkok's Taling Chan area.

Pol Colonel Prayong Lasua said Siriphong later claimed the victims were mother and child, and that Siriphong was dating the woman, who was married to a South Korean man.

However, no DNA test results were available to verify this claim. Police had said earlier that it would take five days to carry out tests on both bodies.

Police are also looking into Siriphong's claim that a 13-year-old Thai girl named Pitchaya was also in the taxi with him and the victims and had been injured by gunshots.