Police are expecting to wrap up their investigation into the murder of a female Chinese tourist found at a waterfall in Hat Yai district on Sept 20 in the next two weeks.
Pol Maj Gen Surachate Hakparn, deputy chief of the Tourist Police Bureau, said on Sunday local police are seeking a warrant to arrest one more suspect who is allegedly involved.
Pol Maj Gen Surachate did not go into details.
Initial investigations found the suspect had left Thailand for China.
Local police have sought cooperation from the Chinese embassy in Thailand to obtain further information on the dead woman and to go after the fugitive suspect, he said.
"We are collecting evidence and witnesses to bring this suspect to justice, and we believe we will finish up the investigation in two weeks," he said.
Citing the autopsy results, Pol Maj Gen Surachate on Sunday said the tourist, identified as Lei Tian, 28, was killed before being thrown into the water at Ton Nga Chang waterfall.
He said investigators are looking into reports that pointed to jealousy as the motive.
He also said that investigators have detained a man, identified as Hai Longzhao, and asked the Immigration Bureau to revoke his visa.
Pol Maj Gen Surachate said the autopsy results indicated the woman had been hit several times with a hard object.
Examiners concluded she was likely to have been dead when her body was dumped in the waterfall.
A taxi driver who had driven Lei to Ton Nga Chang waterfall said the woman appeared to know Mr Hai, as he saw her point at him when they arrived at the waterfall's car park.
His car, a white Honda City, was spotted there and was the last vehicle to leave the spot.