The parents of an Irish girl who was found dead after going missing from a Malaysian resort last year have sued the resort owner for alleged negligence and formally requested a public inquest into her death.

Nora Anne Quoirin, 15, who had special needs, went missing in August from an eco-resort in Seremban, about 44 miles south of the Malaysian capital, while sleeping at night in a room with her siblings.

Following a 10-day search operation, her body was found unclothed and next to a stream, more than a mile away from the resort in which her family was staying.

Malaysian police last year ruled out abduction as a motive, but the family has raised serious concerns over the way the investigation was handled.

A request for an inquest was submitted in writing to the attorney general in December, the family’s lawyer, Sankara N Nair said, but they are yet to receive the response.

Separately, the family has also filed a civil negligence lawsuit against the the resort operator, claiming it was unsafe for Nora.

The lawsuit says a cottage window was found ajar and its latch broken the morning she disappeared. The resort gate was left open at all times without any security and there was no surveillance camera except for the reception area, it alleges. The Quoirins are seeking about 180,000 Malaysian ringgit (£34,000) for losses, bereavement costs and damages for pain and suffering.

The resort owner could not be reached for comment.

Nora, who the family repeatedly said had never previously wandered off alone, had been sharing a room with her brother and sister the night she went missing. When her parents awoke the following morning, she had disappeared and a large window in the hotel room was open.

It is hoped that a public inquiry, which, if approved, would be conducted by a deputy public prosecutor, could provide crucial information about the events that led to her death.

Nair said several questions remain unanswered – including about the window in the room where Nora slept. It was initially reported that the window could only be unlocked from the inside; however, it later emerged that it could be opened from the outside, said Nair. “Therefore there is also a possibility of abduction,” he added. “The police has to rule that out satisfactorily.”

As well as offering the hope of answers about Nora’s disappearance, a public inquiry would also lead to greater scrutiny of the police handling of the case. Nora’s parents have warned the police failed to quickly examine suggestions of a criminal element, and said they did not understand their daughter’s condition.

Nora was born with the neurological disorder holoprosencephaly, which affects brain development, and her family described her as vulnerable. It would have been out of character for Nora to voluntarily leave the family, her parents said.

An autopsy concluded that Nora was likely to have died of starvation and stress after spending seven days in the jungle. However, a complete postmortem report is yet to be released.

Nora’s parents previously said they were shocked Malaysian prosecutors’ decision to conclude that no further action was required in the case, essentially ruling out any inquest.