Thai police have said Hannah Witheridge may have been raped before she was killed.

The body of Miss Witheridge, 23, was found on a beach on the island of Koh Tao on September 15 along with the body of David Miller.

Police investigators said they believe three people were involved in the attacks.

Speaking to the Bangkok Post, Lieutenant General Panya Mamen, commissioner of Provincial Police Region 8, said: “Two of the suspects raped and killed Witheridge while another one witnessed the murder.

“We’re confident we have a very high chance of finding the suspects.”

Officers have collected 200 DNA samples from people on Koh Tao and the results are expected at some point this week.

Two different semen samples collected from Ms Witheridge’s body are the basis for the DNA analysis, the force told the newspaper.

Last week police offered a reward of 700,000 baht (£13,300) for information leading to the arrests of the culprits.

Post-mortem examinations revealed that Ms Witheridge, a speech and language therapy student at the University of Essex who lived in Colchester, died from head wounds.

Mr Miller, 24, from Jersey, was killed by severe blows to the head and drowning.

Hannah Witheridge’s funeral will take place on October 10 in Hemsby.

A number of roads will be closed in the village, in Norfolk, to allow the funeral procession, led by a horse-drawn hearse, to travel from Hannah’s home address to St Mary’s Church.

The convoy will travel slowly from Parklands, a private road, at around 10.45am, along North Road and The Street to St Mary’s Church for the service which starts at 11am. The church service will be followed by a private burial.