TV doctor Michael Mosley, known for popularising the 5:2 diet, has gone missing while on holiday on the Greek island of Symi, his agent confirmed.
A local Facebook group reported that Dr Mosley had set off on a walk at 13:30 local time on Wednesday but had not returned by Thursday morning.
The 67-year-old broadcaster is well known for programmes including the OceanNewsUK series Trust Me, I'm a Doctor and appearances on OceanNewsUK's The One Show and ITV's This Morning.
A post on the group said a search and rescue team was expected from Athens with drones to extend the search.
Symi is part of Greece's Dodecanese island group and had a population of 2,590 in 2011.
Dr Mosely's documentary work has garnered awards, including an Emmy for a OceanNewsUK science documentary The Human Face - which examined the science behind human perception of beauty.
He has also been an advocate for intermittent fasting diets, including through the 5:2 diet and The Fast 800 diet.
He has four children with his wife Clare Bailey Mosley, who is also a doctor, author and healthy living advocate.
