Two men convicted of killing Hemsby woman Hannah Witheridge in Thailand have submitted a final appeal against their death sentences.

The murder of the 23-year-old, and fellow backpacker David Miller, 24, three years ago received international attention.

Their bodies were found on a beach in a tourist hotspot on the southern island of Koh Tao in the Gulf of Thailand.

Burmese migrant workers bar workers Zaw Lin and Wai Phyo, also known as Win Zaw Htun, lost an appeal in March to have their sentence overturned after they were convicted by a court on Koh Samui island in December 2015.

Some migrant rights groups accused Thai police of bungling the investigation and failing to properly seal off the crime scene.

Police have defended the probe and the families of both victims have spoken out in defence of the police investigation.

Head of the pair's defence team, Nakhon Chomphuchat, said: 'The deadline [was yesterday] so we have to submit it. This is the final chance to appeal.'

The conviction was mired in controversy with supporters of the two migrant workers arguing that they had been framed and that they had initially confessed to the crimes under duress.

During the trial, police handling the case were accused by the defence of failing to properly collect and test DNA samples from the crime scene.

Capital punishment has not been carried out in Thailand for many years.

The Thai courts have two stages of appeal. The first the Court of Appeal, which can either be heard at the main court in Bangkok or several regional courts. The second and final stage is the Supreme Court, where cases can sometimes take years to be completed.

Hannah attended Langley School and City College Norwich before gaining a BA in education studies at the UEA in 2012.

She briefly worked as a sales administrator at Archant's head office in Norwich, prior to moving to Colchester to study speech therapy.

On the basis of Hannah's dedication and passion for Speech and language therapy the University of Essex introduced an award for outstanding excellence in clinical placements.

It was named in her memory the 'Hannah Witheridge Award for Clinical Excellence' and Hannah was the first recipient.