An Australian-Kiwi expat living in Thailand has laid bare the “grim” conditions of Thailand’s notorious soi 9 cells, where accused killer Simon Peter Carman is currently being held.

Mr Carman, 45, has been charged with the alleged murder of 17-year-old Tunchanok Donhomla, whose body was found stuffed inside a black suitcase near a railway line in Pattaya, Thailand, with police alleging she was strangled following a dispute over payment for her company.

Thai police officers pose at Suvarnabhumi International Airport in Bangkok with Australian man Simon Peter Carman (C), after he was arrested in the suspected murder of a 17-year-old Thai girl in Pattaya. Picture: AFP

A heartbreaking video of Tunchanok Donhomla’s final moments with her parents has been released before she was allegedly murdered by Simon Carman.

The footage of Ms Donhomla, who has been described as a “loving, fun young girl” by her father Thongchai, 46, shows her smiling and laughing alongside her dad and stepmother Oradee.

Oradee was filmed holding a piece of cake up to the camera as they celebrated Thongchai’s birthday at their family home in Kalasin, northeast Thailand.

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“She didn’t have a lot of money, but she bought me a cake,” an emotional Thongchai told Viral Press.

“We were all so happy. Now that is the last birthday that she will share with me. I feel so sorry for her, the way she died.”

Ms Donhomla was laid to rest in her hometown on Tuesday, in accordance with Buddhist traditions.

Images depict a heartwarming memorial, as hundreds of mourners lined the streets to pay their respects.

The teen’s body was driven through her hometown as hundreds gathered to pay their respects. Picture: Viral Press

Photos of a smiling Ms Donhomla sat among bunches of flowers, as printed signs displayed her full name and age.

Mourners were also seen holding on to a white rope, known in Thai culture as sai sin.

The purpose of the rope is to create a spiritual link between the monks, the attendees and the deceased. Buddhism believes this will help guide the soul towards the after-life and away from earthly attachments.

A photo of Ms Donhomla sits amongst a bunch of flowers. Picture: Viral Press

Hundreds held onto a white rope, a Buddhist tradition that links a soul to the afterlife. Picture: Viral Press

Following the proceedings, Thongchai thanked those involved in the discovery of his daughter’s body.

“I am thankful to everyone who has helped to bring justice for my daughter. I’m proud of the work of the Thai police. There are good police officers who are kind-hearted,” he said.

“I feel the deepest sorrow over this. Even though I am poor, regardless of how society views it, no father would want their child to do what people are speaking of.

Her father spoke of his ‘deep sorrow’. Picture: Viral Press

“Before she left, my daughter said she wanted to see the sea because she had never seen it before. That was her dream and I just wanted her to be happy.

“As her father, I always told her to take good care of herself whenever she left home because I could not be by her side all the time. She promised she would.

“Perhaps we are simply unfortunate. I never imagined that I would have to bring my daughter’s body home. The person who killed my child is utterly heartless.”

Her heartbroken father again called for Mr Carman to receive the death penalty following his arrest for the murder of his daughter.