Police in Malaysia have deployed a helicopter and sniffer dogs in an expanded search for a 15-year-old London girl who disappeared from her bedroom at a nature resort over the weekend.

The district police chief, Mohamad Nor Marzukee Besar, said the operation to find Nora Quoirin, involving more than 150 people, resumed on Tuesday morning, with a helicopter, sniffer dogs and villagers helping in an expanded search through the dense jungle. An earlier mission ending at 3am local time on Tuesday found no further clues.

“We also searched at night but so far, there are no new leads. The operation is ongoing,” he said, adding that further updates would be given at a news conference later.

Nora’s family say they discovered her missing at the Dusun eco resort in southern Negeri Sembilan state on Sunday morning with the window of her bedroom left open, and considered it a criminal matter. Police have said there were no initial signs of foul play.

Speaking at a press conference on Tuesday evening, the district police chief said there was no evidence that her disappearance involved any criminal offence and it was still being investigated as a “missing person”.

The search on Tuesday was focused on a 25-acre area around the hotel but nothing has been found, he said, adding that the search would continue into the night and focus on the area around the river.

The parents of Nora, who has learning and developmental disabilities, 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 during a crisis overseas.

Search and rescue teams at a temporary operation shelter near the resort where Nora went missing. Photograph: Lai Seng Sin/AP

In a statement on Tuesday, the family said: “Nora’s family believe she has been abducted. 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. She never goes anywhere by herself. We have no reason to believe she wandered off and is lost.”

The family arrived on Saturday for a two-week trip at the Dusun, a small private resort located in a durian orchard about 39 miles (63km) south of Kuala Lumpur.

Haanim Bamadhaj, a spokeswoman for the resort, said on Tuesday the Dusun management was baffled by Nora’s disappearance. Resort staff and even some guests had joined in the search, she said. “Our resort has been operating for 10 years and we have never even been robbed. We are doing our very best and praying hard,” she said.

After Nora’s disappearance, she said some guests had cancelled their bookings and that the resort had provided full refunds. Access to the resort has been blocked due to the search operation. The girl’s parents have declined to speak to the media.

Villagers who joined the search expressed concern over Nora’s fate. “This particular jungle, for outsiders they don’t know how to navigate, they get lost. Natives like me, we are used to this jungle,” said Bali anak Akau.

• This article was amended on 15 August 2019 to remove a reference to Nora Quoirin as a British.