Kiwi one of last to see slain woman

A New Zealand man is helping police in Thailand looking for the killer of 21-year-old Briton Katherine Horton, whose beaten body was found in the sea near a popular resort island.

Richie Haskell, 22, is not a suspect, but was with Ms Horton and two friends on the evening of New Year's Day at the resort island of Koh Samui, moments before she wandered off by herself to talk on her cellphone to her mother in Wales.

Police say Ms Horton's mother heard her scream just before the line went dead. She was strolling along Lamai beach, where witnesses also say they heard a scream.

A jet skier on Monday morning discovered Ms Horton's body, still wearing an evening dress, in the sea near Lamai beach on the island's southeast coast.

Police Lieutenant Colonel Dr Pattana Kitkailart, who performed the autopsy on Ms Horton's body in Bangkok, said she had been beaten about the head and body, and had drowned.

Lieutenant Colonel Thanongsak Aksornsom, of the Koh Samui police station, said there was no evidence of rape and it appeared a single person had killed her. "We hope to get the killer very soon," he said.

Police have interviewed a dozen Thai men and foreigners, including Mr Haskell, who also provided a police statement and blood sample.

Four British backpackers, all staying at the New Hut, also signed statements and gave blood samples. One of the men, Wesley Thomson, 27, said they had done so voluntarily.

Police are yet to issue any arrest warrants, but want to speak to four Thai men who arrived at Lamai beach on two motorbikes on New Year's Day.

"The national and local police are launching an all-out effort to conclude the case and get the killer in this important case as soon as possible," said police Major Warawej Winitnetayanonda, chief of Surat Thani provincial police where Koh Samui is located.

Ms Horton's friend and travelling companion, Ruth Adams, identified Ms Horton's cellphone found on the beach. She was interviewed by police and left the station with her head bowed, refusing to speak to reporters.

Ms Adams's parents, Michael and Jenny, from Bromley, Kent, said in a statement: "It was only a week ago that we took Kath and Ruth to Heathrow in a state of great excitement. Our hearts go out to Kath's family at the loss."

They said their daughter had lost a "vivacious and supportive friend" and was devastated.

Koh Samui, 450km south of Bangkok, is jammed with foreign tourists at this time of the year.