Survival expert Ray Mears is helping with the search for a missing County Durham school teacher.
Darren Blyth, 55, was last seen leaving his home in Trimdon Station, County Durham, to take photographs at local beauty spot Hawthorn Dene, around 12 miles away, on Wednesday evening.
His wife Mel said he had been "stressed about the risks of Covid and the effect on his role as a teacher" and that it had affected his mental health.
And now Mears, a family friend, has been helping police by studying the area where he was last sighted, The Cleveland Way, and suggesting where he might go for food and shelter.
The 55-year-old is a biology teacher at Stokesley School and Sixth Form College and was reported missing by wife Mel, 53, when he didn't return home.
Family friend Suzanne Helm said Mel is currently out on The Cleveland Way searching for Darren.
And although Mears isn't out in the countryside searching for Darren, Suzanne said his expertise is helping the family with their enquiries.
She said: "Ray is providing support, advice and giving some ideas on where the best places to look could be.
"The sightings that we've had, although they're not 100%, they're very credible.
"Mel feels that she needs to get out there talking to locals who know the area and the paths."
Darren is described as 5ft 10in, of slim build and with short grey hair, and was last seen wearing a black North Face coat and grey outdoor trousers.
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His family have since issued a heartfelt plea for him to return home.
Daughter Katrina, 36, said: "As a husband and a father he is priceless.
"Nothing in the world can replace him. We just want him to come back safe."
Anybody with any information relating to Darren’s whereabouts has been asked to contact Durham Police on 101 as soon as possible, quoting reference number 005 of April 15.