By Joe Inwood and Insaf Abbas, in Symi for BBC News
TV presenter Dr Michael Mosley has been missing since Wednesday. Photo: Facebook
The search for missing TV and radio presenter Michael Mosley has shifted to a remote mountainous area on the Greek island of Symi.
The 67-year-old, known for his TV programmes and BBC Radio 4's Just One Thing podcast, vanished on Wednesday while on holiday.
Mosley was reported to have left Agios Nikolaos beach by foot on Wednesday at 1.30pm local time, and new CCTV footage seen by PA news agency showed him later entering a mountainous path inland from a nearby village.
A search and rescue operation, involving helicopters and drones, started up again on Saturday morning.
At 6am local time, firefighters started searching a 6.5km radius over a mountainous area that is surrounded by sea, said Manolis Tsimpoukas who organises searches for missing people on the Dodecanese Islands, of which Symi is a part of.
Asked if there had been any sign of Mosley, he said there had been "nothing".
A source directly involved in the search told BBC News the search was focusing on the mountainous area between areas of the island Pedi and Symi. The source described it as "not easy terrain".
One theory that has emerged was that Mosley was trying to take a much longer route than previously thought, passing over miles of exposed hillside. Mosley's accommodation was in the main town.
CCTV images appear to capture the broadcaster in Pedi's main street holding an umbrella about 20 minutes after leaving the beach.
This CCTV image appears to show broadcaster Michael Mosley. Photo: Live News / Mega TV via BBC News
The BBC has seen a second piece of CCTV footage from a nearby premises showing a man wearing the same clothes and carrying the same umbrella which was time stamped at 1.50pm.
Officials are now understood to be excluding the possibility the father-of-four came to harm while walking between the beach and Pedi.
Separate CCTV, from a house at the edge of Pedi's marina at the far end of the village, showed Mosley later entering a mountain path at about 2pm local time, PA said.
A member of the rescue team described the search as a "race against time" and said he could be "anywhere".
"The path is not easy to follow, if he took a wrong turn, he would be lost," she told PA.
His four children had arrived on Symi to help with the search. His wife Dr Clare Bailey Mosley had also been searching the island joined by her British friends, Symi's mayor said.
All patrol boats, private boats and commercial boats near the island had been searching for Mosley, Symi's coastguard said, while police and firefighters had been using drones and a sniffer dog to try to locate the missing presenter,
Divers had been "looking into the water" with the help of the Hellenic Coast Guard.
Symi's mayor Eleftherios Papakaloudoukas said the search would continue until Mosley was found.
He added he was unsure why the missing presenter would try to make a long, potentially arduous journey in such heat, but he hoped the presenter was found "safe and alive".
Greek police said Mosley left his wife on the beach on Wednesday, before setting off on a walk to the centre of the island.
His phone was found where he was staying with his wife, who reported him missing, a police spokesperson told BBC News.
An appeal saying he was missing was posted on a local Facebook group on Wednesday, alongside a picture of Dr Mosley wearing a blue cap, polo shirt and shorts.
"Have you seen this man? He set off to walk back from [Agios Nikolaos beach] at about 13:30 and failed to make it home," it said.
Symi is part of Greece's Dodecanese island group and sits about 19km north-west of Rhodes. In the 2021 census it had a population of approximately 2,600 people.
The majority of its beaches are remote and people are advised to take boats to visit them.
This story was originally published by BBC News.