Rescuers continued searching for British TV presenter Michael Mosley on the mountainous Greek island of Symi on Saturday, the third day of a wide operation launched after he was reported missing by his wife.

The 67-year-old doctor and healthy living advocate, who has endorsed fasting and offered tips on sleep and diet, was last seen at 1:30 p.m. (1030 GMT) on Wednesday.

He disappeared after he set out on a stroll in searing temperatures along a rocky coastal path from Agios Nikolaos beach to the village of Pedi. Mosley did not have his mobile phone with him, hampering tracing efforts.

Police, the fire brigade and volunteers have been searching on and off the island in the eastern Aegean assisted by a helicopter, drones and rescue dogs.

On Saturday, police searches shifted focus to an area opposite Agios Nikolaos, between Pedi and the beach of Agia Marina.

"The search continues," spokeswoman Constantina Dimoglidou told Reuters. "We are investigating on foot another rocky part, the wider area of Agia Marina."

Images shared with Reuters from a security camera in Pedi showed what is believed to be Mosley, strolling by at 1:49 p.m. on Wednesday, holding an umbrella, suggesting he may have made it safely off the coastal path.

Symi Mayor Lefteris Papakalodoukas said that the images and video footage from security cameras had helped sketch out what authorities believed was Mosley's possible route, which he described as "unconventional".

They indicated that he may have continued further through Pedi into another challenging area around Agia Marina, the mayor said.

"He chose paths which are very difficult to walk in such temperatures and under any circumstances," Papakalodoulkas said. "Cameras show that he did not take the expected way back home."

Symi is about 10 miles (16 km) long and has 2,500 residents. Its remote beaches were filled with sunbathers on Friday.