Haunting CCTV has emerged showing the last sighting of a British teenager murdered in Thailand as police search for a second girlfriend and question a suspect.

Dual national Woramet Ben Taota, 16, borrowed his mother's blue scooter and was seen riding with a girl on the back before he was found dead the next day in Lampang province on May 7.

The footage shows how Ben had a girl police said he was 'romantically involved with' Suraphltchaya Khamsa, 16, riding pillion with him at around 4:25 pm as they visited her grandfather. They dropped off another girl, also seen on the bike, then rode away together at 7:18 PM local time in darkness.

Ben's first girlfriend, Yam, has now been found and she is safe. Police have ruled her out of the case. However, there are fears for his second girlfriend Suraphltchaya following the arrest of suspect Chaiwat Boongarin, 44, who had known the pair ‘for several years'.

Police Major General Mongkol Sampawapol, commander of Lampang Provincial Police, said officers are still searching for Suraphltchaya as she was ‘the last person to see Ben' before he was killed.

He said: ‘Suraphltchaya's nickname was Ping Pong. She also had a close romantic relationship with the deceased. She is still missing and we are actively searching for her. She was the last person to see Ben.

‘A suspect has been apprehended who had known the victim for a long time. He denies having any involvement in the death. However, we believe he is involved and it is connected to drug dealing in the area.'

Police said the suspect had been released from prison around eight months ago following previous convictions for sex crimes.

They claimed that Chaiwat was seen riding his black Honda Wave motorcycle without a license plate on May 6 at around 9 PM and parked it at his relative's house with a young woman they believe is Ben's girlfriend, Suraphltchaya.

The motorcycle was found by officers this morning, May 9, behind a cow shed close to the home.

Police Major General Mongkol Sampawapol added: ‘The suspect told his relative that he wanted to leave his motorcycle at their house.

‘He told them that he was looking for a rental house for his mistress. He then left the house with another motorcycle and returned the next morning.

‘After that, he rode the black Honda Wave and left it near the hut before officers found it on May 9.

‘We are still searching for the young woman and believe that she is still safe.'

Police officers from the Mae Tha district said they received a report on Sunday morning that the teenager, known to friends as Ben and was half Thai and half British, had been found dead in a grove in the Ban Than district.

Officers found in his black shoulder bag a smartphone charger and a red wallet containing his ID card and bank card. His smartphone and cash were missing, with police suggesting he could have been robbed for the gadgets and money.

Police believe Ben was killed elsewhere and dumped in the woods, as there were no signs of struggle where his remains were found. They said he had head injuries consistent with severe trauma.

Police Colonel Sittisak Singtongla, superintendent of the Mae Tha Police, said: 'The station received a notification at 10:15 am that a deceased person was found in the undergrowth.

'The investigating team went to the area and found the victim with blood stains all over his face. The face and head were found to have been beaten with a hard object until swelling and bruising was caused. There was also a deep wound in his face.

'The body has been taken to hospital for an autopsy.

Officers interviewed Ben's mother, Ooy Taota, who is understood to be separated from Ben's British father, who now lives back in the United Kingdom.

Ooy told police that her son had said goodbye to her on Saturday evening and said he was 'going to work with friends' but he did not give any more details to her.

She was pictured today breaking down in tears as she visited the spot where Ben was found dead.