Malaysian police will play the recording of a family member’s voice over loudspeakers to help try to find a British teenager missing in the country.
Superintendent Mohd Nor Marzukee Bin Besar also said 252 people are now involved in the search for Nora Quoirin.
A helicopter, drones and dogs are also being used to trace the 15-year-old who has been missing since Sunday.
The police chief said: “We have had a long discussion with the family to determine who Nora has the closest relationship to and whose voice she would respond strongly to.
“We have decided to make a recording and use a loud speaker.
“We have to respect the sensitivities of this case. We need to make the recording and will start using the loudspeaker this morning.”
He added that police will confirm later which family member’s voice will be used, adding he hopes it will “jump start” Nora to respond if she hears it.
The police chief continued: “If she is exhausted or unconscious, if she has managed to find water and is awake, we hope the voice will alert her.”
The family of Nora, who is from London, have said they remain hopeful after police leading the investigation refused to rule out a “criminal element”.
The teenager disappeared from the Dusun forest eco-resort in southern Negeri Sembilan state.
Her family released a statement expressing their “deepest gratitude” to the Royal Malaysia Police and others helping the search.
The force has analysed fingerprints found in a resort cottage from which Nora was reported missing, despite previously saying there were no initial signs of foul play.
Her parents Meabh and Sebastien, an Irish-French couple, were “too upset to speak themselves” but have issued a statement through the Lucie Blackman Trust.
The charity helps crisis-struck British nationals overseas.
The family’s statement said: “We would like to thank our embassies, the local community, and the staff here at the hotel and anyone else who has offered help to find Nora.
“We also welcome the assistance of the French, British and Irish police.
“We are completely overwhelmed by the support we have received from all over the world.”
The statement added: “This is extremely traumatic for the whole family.”
The parents believe their daughter, who has learning and developmental disabilities, was abducted.
They arrived at the resort, which is about 40 miles south of Kuala Lumpur, with Nora and her younger brother and sister on Saturday.
Their statement added: “We must remain hopeful.
“And we ask everyone to keep Nora in their thoughts, and to continue to support the ongoing search for her.
“Nora is still missing, and she is very vulnerable, and we need to do everything we can to bring her home.”
Deputy police chief Che Zakaria Othman said police have received the laboratory results of fingerprint samples taken from the Quoirin family’s accommodation.
Investigations are still ongoing to identify who the fingerprints belong to.
He said the prints were at an open window in a downstairs hall, not in the bedroom upstairs where Nora was sleeping with her siblings.
Police added they were “not ruling out any possibility” and believe Nora is still in the area.