Divers are searching for missing TV doctor and columnist Michael Mosley off the Greek island of Symi.
The local police department restarted scouring the island on Friday morning after pausing the search-and-rescue operation for the 67-year-old British national on Thursday night.
Police and firefighters have been using drones to try to locate Mosley, who vanished after setting off on a walk to the centre of the island on Wednesday.
Symi deputy mayor, Ilias Chaskas, confirmed that "divers are looking in the water", and the local coast guard have joined the rescue efforts.
Symi's coast guard said: "All our patrol boats are searching … about five and also all the private boats, commercial boats know about the incident and they look for (him) also, in this area, (so this is) the private, the commercial and the patrol (boats looking)."
A spokesperson for the Greek fire service said: "The search continues today with seven firefighters, one drone checking the wider area, and we (are) co-operating with the Hellenic Police Office."
The spokesperson also confirmed that Greek police are using sniffer dogs in the search.
Local people from Symi, which is part of the Dodecanese island chain and is about 25 miles north of Rhodes, along with police drafted in from outside the island, are searching the Pedi area and surroundings on Friday morning, the mayor’s office said early on Friday.
The area where Mosley went missing is experiencing hot temperatures, forecast to reach highs of 36C on Friday, according to the Hellenic National Meteorological Service.
It also has a yellow weather warning for high temperatures in force in Rhodes and the surrounding islands including Symi.
Greek police said it was informed of the "disappearance of the 67-year-old British national on the island" on Wednesday, according to a statement.
Police then asked for assistance from the Greek fire service, with six firefighters, a vehicle and a drone team arriving from Rhodes at about 2pm (12pm BST) on Thursday.
A woman reported seeing Mosley, known for popularising the 5:2 diet and for his appearances on The One Show and This Morning, in the Pedi area on Wednesday.
Mayor of Symi Eleftherios Papakalodoukas said firefighters had told him they believed it was "impossible" Mosley was still there.
He told the BBC: "It is a very small, controlled area, full of people. So if something happened to him there, we would have found him by now."
A local Facebook group said Mosley went for a walk from Saint Nikolas Beach at about 1.30pm Greek time on Wednesday.
A British Foreign Office spokesman said: "We are supporting the family of a British man who is missing in Greece and are in contact with the local authorities."
Mosley is known for being a columnist for the Daily Mail and has made a number of films about diet and exercise.
The broadcaster fronted the Channel 4 show Michael Mosley: Who Made Britain Fat? and was part of the BBC series Trust Me, I’m A Doctor.
He also lived with tapeworms in his gut for six weeks for the documentary Infested! Living With Parasites on BBC Four.
Mosley received an Emmy nod for BBC science documentary The Human Face, presented by John Cleese and featuring a raft of famous faces, including Elizabeth Hurley, Pierce Brosnan and Sir David Attenborough.
He also advocated intermittent fasting through the 5:2 diet and The Fast 800 diet.
Mosley has four children with his wife Clare Bailey Mosley, also a doctor, author and health columnist, who wrote the recipe book Fast 800 Easy.
The couple, who have hosted theatre show tours together, recently attended the Hay Festival in the UK, where Mosley presented a special edition of his Radio 4 series and podcast Just One Thing.
Source: Press Association
