Simon Peter Carman, the Australian man charged with murdering Thai teenager Tunchanok Donhomla, says he acted in self-defence to stop her from stabbing him.
The 45-year-old spoke exclusively to the ABC's Foreign Correspondent program in a private visitors' room at Pattaya Remand Prison, where he has been detained for almost two months.
"I'm hoping and praying that I get released," he said.
"I have not done anything wrong. I shouldn't be here … I do not understand what's going on."
Thai police have accused Mr Carman of picking up the 17-year-old along Pattaya's popular Beach Road in the early hours of June 25, then killing her and discarding the body.
In a 30-minute interview, conducted under the close watch of a prison guard, Mr Carman said he was innocent and did not intend to kill the teenager.
"I feel deeply sad. I obviously wish it never happened, but it was unavoidable," he said.
"All I was trying to do was restrain her from stabbing me."
The ABC is the first foreign news organisation in at least 15 years to receive permission to interview a foreign inmate in a Thai prison. The interview was permitted on the condition that prison officials could review the ABC's footage for security reasons, and that prison conditions were not discussed. The interview was carried out with Mr Carman's consent.
He faces four charges, including murder, concealing a corpse, and abducting a minor for indecent purposes.
If found guilty of murder, he faces the death penalty or life in prison.
"I pled not guilty, and I remain not guilty of all four charges," Mr Carman said.
Mr Carman told the ABC he did not have a lawyer yet and had not received any visitors apart from Australian embassy officials.
Thai police wrapped up their investigation last week and intend to pass the case to prosecutors today.
Tunchanok Donhomla's father, Thongchai Donhomla, said he wanted Mr Carman to receive a life sentence or the death penalty to "serve as a lesson for others".
"I want Simon to receive the harshest punishment because I have lost my child," he told the ABC in an interview last week.
Ms Tunchanok, known affectionately by her friends and family as "Cake", was last seen alive on June 25.
CCTV captured her walking hand in hand with Mr Carman into the elevators of his condo building.
It later captured Mr Carman dragging a large suitcase out of the building and transporting it on a motorcycle at night.
Two days later, police found Ms Tunchanok's body in the suitcase, which had been dumped along railway tracks near Mr Carman's accommodation.
Mr Carman was arrested at Bangkok's international airport on June 27 while trying to board a flight to Perth, and has been in Thai police custody since.
In the interview with Foreign Correspondent, Mr Carman maintained he had acted in self-defence.
Mr Carman said he first met Ms Tunchanok on the street, where she was accompanied by two friends. He said the 17-year-old then followed him back to his accommodation.
"I honestly do not know why she followed me home," he added.
When the ABC told him there was CCTV showing them entering the building holding hands, Mr Carman said: "I cannot remember that, but if it was hand-in-hand, I believe you."
He said he was not aware Ms Tunchanok was a minor at the time, and believed she was roughly 25 to 35 years old.
Mr Carman said when they got to his room he "gave her 500 baht ($21) … for nothing. And she wanted more money and then she pulled a knife".
He said he repeatedly asked Ms Tunchanok to "put down the knife" during a physical struggle, and that eventually "she went limp".
When asked if he had called anyone, including an ambulance, Mr Carman said he had not because he "didn't trust the police".
Pattaya Police Colonel Anek Srathongyoo said his investigation team would submit its case file to the Pattaya prosecutor's office today.
Prosecutors will then have until September 18 to indict Mr Carman.
The police autopsy report, revealed exclusively to the ABC last week, concluded Ms Tunchanok had died from suffocation.
"The autopsy report said that Cake had a brain injury and she suffocated. She had no other injuries," Colonel Anek told the ABC last week.
"We also collected Simon [Carman's] DNA and matched it to DNA found on Cake's body."
Ms Tunchanok's auntie Mirantee Thanachai, who was among those who identified the teenager's body, said she was upset by Mr Carman's statements.
"I'm so angry that he claimed Cake tried to hurt him and that he was just defending himself," she told the ABC.
"If things weren't working out, he should have just let her go."
Ms Tunchanok's father told the ABC he was "deeply heartbroken" by the case.
"I always told my child to be a good person, never to cheat or harm anyone. But if a bad situation happens, I always told her never to back down to anyone and to fight to the very end," Mr Thongchai said.
"I don't ask for much. I just hope my child gets the justice she deserves."
