Australian murder accused to plead guilty to charge of concealing Thai teen's corpse

In short:

Simon Peter Carman has appeared in a Thai court court over the alleged murder of Tunchanok Donhomla.

Ms Tunchanok's family is seeking damages in a civil case against the 45-year-old Australian, who has maintained his innocence.

The civil and criminal cases against Mr Carman are expected to be heard simultaneously.

The family ofThai teenager Tunchanok Donhomla is seeking $70,500 in compensation from her alleged murderer, Australian Simon Carman, a court has heard.

Mr Carman has maintained his innocence, telling the court the 17-year-old girl was "responsible for her own death".

Police and rescue volunteers discovered the naked body of Ms Tunchanok, who was known as Cake, inside a discarded suitcase in the popular seaside city of Pattaya in June.

Prosecutors charged Mr Carman with intentional murder, concealing a corpse, moving or destroying a corpse, and abducting a minor for indecent purposes.

If found guilty, he faces life imprisonment or the death penalty in Thailand.

Family files civil suit

On Sunday, Ms Tunchanok's cousin Khanitta Nongkhampoon told the ABC that the family had filed a civil lawsuit against Mr Carman.

They are seeking 1.65 million baht ($A70,500) in compensation for the 17-year-old's death.

In Thailand, victims of crime and their family members are permitted to lodge civil cases seeking monetary compensation from alleged perpetrators in addition to any criminal prosecution.

Ms Khanitta said the money would help Ms Tunchanok's father pay for funeral expenses, as well as compensate him for the financial support his daughter would have provided in the future.

"Nobody wants money from this. They want the person's life back. She should have had a future that went much further than this," Ms Khanitta said.

Almost four months after Ms Tunchanok's death, Mr Thongchai said his grief remained overwhelming.

"Normally, she would be at home when I get back from work. I would see her every day. Now when I go back, there's nothing left but emptiness," he said through tears.

"I want the case to be pursued to the fullest extent. Deep down, I wish for the death penalty, but I think it probably won't go that far.

"I'll leave it to the law to take action to the maximum extent, because I have lost my only child."

The Office of Rights Protection and Legal Aid has assisted Ms Tunchanok's family to apply for a government lawyer to help them pursue the civil lawsuit and to also assist with the ongoing criminal case.

Court will give case 'higher priority'

An official from the Office of Rights Protection and Legal Aid said the civil case would not affect the outcome of the criminal case against Mr Carman.

Ms Tunchanok's family would only be awarded compensation if the Australian was convicted of the charges against him, they added.

"If they file a civil lawsuit separately, they will have to pay court fees," the official said.

"But since this is a civil case related to a criminal case involving a murder that has caused damage to life, they can bring the civil claim as part of the criminal proceedings without having to pay court fees."

The legal aid office confirmed that the civil and criminal cases against Mr Carman would be heard simultaneously.

The court will issue its rulings on both at the same time, according to the office.

"Because this is a high-profile case that has occurred recently and involves a tourist, the court will give it higher priority and try to expedite the proceedings," an official from the office who did not want to be identified said.

The office said the case was "unlikely to take beyond the first half of next year".

"We need to present as much evidence as possible to help the court understand the family's circumstances and consider their claim sympathetically," the legal aid office said.

"However, an important factor is also how much Simon [Carman] can afford to pay."

Carman in custody since June

Mr Carman was represented in court by lawyer Sorasit Pongin, who told the ABC he had been retained by the defendant's mother.

The West Australian man has been held at the Pattaya Remand Prison since his arrest in June.

He denied all charges when he appeared in court today.

"There was no intention at all [to kill Ms Tunchanok]. I didn't know what to do," he said to a member of his defence team.

"Cake [Ms Tunchanok] is responsible for her own death."

When Mr Carman was asked by the judges if he would agree to pay compensation to Ms Tunchanok's family, he responded: "I'm not guilty so I cannot plead guilty."

"I am innocent and they cannot lock up an innocent man," he said.

"Why [do] I have to pay compensation when I haven't done anything wrong? I do feel bad for the family."

Ms Tunchanok was last seen alive on June 25, when she was recorded on CCTV walking hand in hand with Mr Carman into the elevators of his condo building about 3:30am.

Mr Carman was later seen on CCTV dragging a large suitcase out of his room and transporting it on the back of a motorcycle.

Two days later police found Ms Tunchanok's body inside a suitcase that had been dumped along railway tracks near Mr Carman's accommodation.

A police autopsy found that the teenager died from suffocation.