A British tourist is being investigated over the death of a Thai prostitute who was found dead in his hotel room - claiming he did not notice her decaying corpse for four days.

Bearach Beataidh, 71, was last seen kissing and holding hands with Duangta Khampongsom, 45, as he took her to his bedroom at a guest house in 'Sin City' Pattaya in eastern Thailand on December 18.

She was never seen alive again - but Bearach, from County Down, Northern Ireland, was captured on CCTV emerging from the room looking nervous four days later on December 22.

Building caretaker Prayoon Chinsai, 57, called police later that morning when he noticed a foul odour coming from the studio style room . When he knocked and no one answered, he used a spare key to open the door - only to find the woman's half-naked body rotting on the bed.

Officers arrived at the building and found the Brit, who also holds an Irish passport issued in Ireland, at a nearby bar.

He said he was aware of the body - and had been sleeping next to it - but did not file a report with police as he claimed he 'did not know she was dead'.

Police Captain Puttharak Sonkhamhan of the Pattaya City Police Station said officers are questioning Bearach further over his bizarre statements.

He said: 'The woman had been dead for at least three days. Her body had started to decay and bloat, giving off a foul smell throughout the room.

'She was wearing only denim shorts and nothing on her top half. An inspection of the room found no signs of a struggle or ransacking.

'It would be difficult not to notice she was dead as her body was already decomposing. There was also fluid and blood on the bed.'

Cops searched for the British pensioner and found drinking him at a bar along Jomtien Beach. He was said to have been dazed and confused when he was detained.

Bearach claimed he had invited Duangta, a prostitute from a nearby bar, to stay in his room after she was allegedly assaulted by an unknown attacker on December 18.

CCTV footage obtained by police shows the Duangta in a black shirt and white cap walking with the tourist along the hotel corridor on December 18 evening.

Bearach was then seen on December 22 emerging alone from the room. He was captured checking both sides of the hallway before heading to a row of bars on the beach.

He allegedly told police: 'She kept vomiting and sleeping the whole time, but I did not think it was anything abnormal. I understood that she felt weak and exhausted. We last spoke on December 19.'

Bearach claimed he did not realise she had died 'because there was no unusual smell' in the room. He denied hurting or killing the deceased.

Bar owner Kaew, 65, described the dead woman Duangta as an 'alcoholic' and a 'regular heavy drinker'. She claimed to have seen the British holidaymaker rejecting Duangta on the night of December 18.

Duangta's former co-worker Pim, 46, also labelled her as a barfly.

She said: 'Duangta had known the British man for less than two weeks. I don't think he killed her, but I find it strange that she died in his room.'

Duangta's body was taken to the Bang Lamung Hospital for a post-mortem examination. Doctors have not clarified the cause of her death.

Police Captain Puttharak added: 'We summoned the British man to the police station for further questioning. Forensic police are continuing to collect fingerprints and DNA because we do not believe his testimony. All CCTV is being checked.'

Former fishing village Pattaya became popular with American troops on 'rest and relaxation' breaks in the 1960s when the U.S. military had bases in Thailand. In the ensuing years, the coastal resort spawned into a semi-barbarous sex-tourism Mecca.

Embarrassed officials have made progress in gentrifying the region with family tourism projects but a ravenous nightlife industry has remained, and continues to attract men from around the world.