Malaysian police are analysing fingerprints found in a forest resort cottage where a 15-year-old London girl was reported missing, and have not ruled out a possible criminal element.
Police had earlier said there were no initial signs of foul play in Nora Anne Quoirin's disappearance from the Dusun eco-resort in southern Negeri Sembilan state on Sunday morning.
Her family discovered her missing from her bedroom and say they believe she was abducted.
Negeri Sembilan deputy police chief Che Zakaria Othman said a forensic team was analysing fingerprints found in the cottage where the girl disappeared from but declined to give details.
He said it was the window in a downstairs hall that was left open, and not the one in the bedroom upstairs where the girl was sleeping with her two siblings.
He declined to say if the window could be opened from the outside, saying the investigation was ongoing.
"Although we classified this case as a missing person but we are not ruling out any possibility... the scale of investigation and the search and rescue is very big for a small place here," he told a news conference. He said the investigation includes a possible criminal element.
Mr Zakaria said a special team from federal police headquarters as well as from forensics and criminal investigation departments were assisting.
The rescue operation involves more than 200 people working on shifts through the night but police still have no clues to the girl's whereabouts and are appealing for information, he said.
"We still have hope and believe that she is still in the area. There is no information to show that she has left the area," he added.
The girl's family insisted in a statement on Tuesday that they did not believe she had wandered off on her own.
"Nora's family believe she has been abducted," the statement said.
"We are especially worried because Nora has learning and developmental disabilities, and is not like other 15-year-olds. She looks younger, she is not capable of taking care of herself, and she won't understand what is going on."
Her parents are an Irish-French couple who have lived in London for about 20 years, according to the Lucie Blackman Trust, a British charity that supports people involved in a crisis overseas.
Nora arrived with her family on Saturday for a two-week stay at the Dusun, a small resort in an orchard next to a forest reserve about 40 miles south of Kuala Lumpur.
Some of the girl's relatives were seen trekking at the hill in the search on Wednesday. Police blocked access to the resort due to the search operation.
Officers have expanded the search to the riverbed at the foothill of the resort on the assumption that she could head downhill to try to find water. Local villagers and police dog teams have also been deployed to try to find her.