Gareth Huntley, 34, has not been seen since he started a trek to a waterfall in Tioman Island, off the south-eastern coast of the country’s mainland, last Tuesday.
No 10 confirmed Mr Cameron had spoken to the Malaysian prime minister. A spokesman said: “The PM thanked prime minister Najib for the extensive efforts of the Malaysian authorities over the past few days and said that the UK was considering what more it could do to help if required.”
Mr Huntley’s mother Janet Southwell, from Bradford, who arrived in Malaysia yesterday, hopes she will be the “friendly face” he needs when he comes out of the jungle.
She said: “This is an incredibly tense and stressful time... It is vital that the intense jungle search continues and we hope everyone can pray with us for Gareth’s safe return.”
In a call home to her son Mark, she said the search included helicopters and speedboats.
Mr Huntley, now of Hackney in east London, went to Woodhouse Grove School at Apperley Bridge, near Bradford, and is on a sabbatical from his job in the City. His family believe he may still be alive but is injured and needs help.