'We will not lose hope.' Michael Mosley's wife speaks about his disappearance.

The search effort for the well-known UK TV personality Dr Michael Mosley who was reported missing in Greece earlier this week has intensified.

The 67-year-old British doctor and medical journalist, who is the author of the popularised intermittent fasting 5:2 Diet, was holidaying on the island of Symi, Greece. After he failed to return from a walk by 7:30 pm on Wednesday, his wife Dr Clare Bailey, reported him missing to local police.

She has since released an emotional statement saying she and her family would "not lose hope" after firefighters redirected their search to a maze of tunnels commonly referred to as 'The Abyss'.

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Local authorities launched a small operation in an attempt to retrace his route on the island before they pivoted to the different area. 'The Abyss' features rocky terrain including water-filled "bottomless" tunnels, per the Herald Sun, and firefighters are struggling to see or find anything. 

His wife has since released a statement, writing, "It has been three days since Michael left the beach to go for a walk. The longest and most unbearable days for myself and my children.

"The search is ongoing and our family are so incredible grateful to the people of Symi, the Greek authorities and the British Consulate who are working tirelessly to help find Michael."

Dr Bailey added, "We will not lose hope."

However, locals say the search for Dr Mosley is a "race against time" as the tunnels of The Abyss can quickly fill with seawater. 

"It's like a deep system of tunnels, but it is full of water and can spread for kilometres," a local waiter told The Daily Telegraph. "There is a reason they call it 'The Abyss'. There is something very strange going on."

Speaking to Greek publication News.gr, Symi's deputy mayor Nikitas Gryllis said, "It is a strange area, a mountain with many blind and dangerous spots, which must be combed metre by metre."

Meanwhile, the daughter of the mayor of the Greek island said the entire community is pulling together to try to find Dr Mosley. She said, per the Independent, that the community is "close". 

"We're good people actually here. Everybody is looking for him."

CCTV footage shows Dr Mosley walking out of a fishing village, heading towards a rocky path that would take him up a mounting in 37^oC heat, according to The Sun — a move that rescuers describe as "inexplicable".

According to the Evening Standard, a search and rescue team was sent earlier this week from Athens, using helicopters, drones and police dogs in an attempt to locate Dr Mosley. A community Facebook group on Symi also shared a photo of the doctor, appealing for information.

The post reads: "Have you seen this man? He set off to walk back from St Nick's at about 13:30 and failed to make it home.

"His friends are concerned as it is six hours since they last saw him. His name is Dr Mike Mosley and he is a familiar face for many British people as he has appeared on the BBC. The police and coast guard have been informed EMAK, the island’s rescue team, is also involved."

A police spokesman told the Daily Mail Mosley was last seen at 1:30pm on Wednesday, when he went for a walk along a coastal path. 

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The spokesperson said: "He was at the beach of Ag. Nikolas with another couple when he decided to go back to his home in the area of Pedi of Symi.

"It was around 1:30pm and he forgot his phone at the beach. Any and every attempt to track him down has not produced any result.

"We have now asked the fire brigade to assist in the operation in the case that he may have slipped, tripped, fallen, even bitten by a snake, remaining injured somewhere.

"There is just no trace of him. None whatsoever and that means that for us at least, every potential scenario is open and being investigated."

Dr Mosley is well known in the UK for programs including the BBC series Trust Me, I'm a Doctor, The One Show and he regularly appears on breakfast show This Morning, as well as hosting BBC podcast Just One Thing 

He has also presented Australia's Health Revolution and Australia's Sleep Revolution on SBS.

Dr Mosley is married to 62-year-old Dr Clare Bailey Mosley, who is also a doctor, author and health columnist. They have four children together.

Feature image: Getty.