A van driver accused of drugging and raping a 13-year-old girl surrendered to the police on Monday, saying he was innocent.

Police said the suspect, whose name was withheld, had turned himself in to Waeng Noi Police. He brought his van along to be examined by investigators.

The suspect denied all the allegations against him, saying he had worked as a public van driver for 30 years and that he would never commit such crimes.

The incident reportedly took place on Oct 1, after the girl's parents decided to hire a public van to drive their daughter from Khon Kaen to Bangkok.

The victim's grandmother said the girl was supposed to arrive on the morning of Oct 2, but she didn't arrive until around noon.

The driver blamed the delay on roadworks.

After returning to Khon Kaen with the same driver on Oct 31, the girl started having trouble sleeping because of nightmares.

The grandmother said her granddaughter claimed to have been drugged and sexually assaulted by the van driver on the way from Khon Kaen to Bangkok.

Around dawn, the girl said the suspect urged her to have a sip of water, promising if she drank it, he would bring her to meet her parents.

The girl said when she complained about feeling dizzy, she was raped and threatened by the suspect.

The girl also claimed there were bloodstains on the van's seats, the grandmother said.