Ivan Meyer, 45, left his home in Edinburgh and travelled by train to the Stirling village of Crianlarich on Monday.

Police Scotland said Mr Meyer is believed to have arrived from the A82, south of the village, to walk up the mountains of An Caisteal and Beinn a' Chroin.

Inspector David Marr, from Stirling Police Station, said: "Ivan has not been in touch with friends or family for the past day and this is extremely out of character for him.

"As time passes, concern for his welfare continues to grow."

Mr Meyer is around 5ft 11in tall with a lean build and dark greying hair and stubble.

He is believed to be wearing hiking clothing, including black trousers, a black top, brown hiking boots and a maroon and light-blue striped hat.

Officers said he is also known to be in possession of a light-grey backpack, a green one-man tent and two purple hiking poles.

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Inspector Marr added: "We are carrying out extensive searches in the area, with the assistance of partner agencies, and are asking for anyone with information on Ivan's whereabouts, or any possible sightings, to please come forward."