The family of a missing marathon runner in Greece say they are "increasingly concerned" for his safety.
Experienced endurance athlete John Lawton, 62, from Alsager, Cheshire, disappeared during an off-road race near the village of Kardamili in southern Greece on April 8.
His wife, Lynda, son Steve and brother David have joined police and volunteers in Greece in the search for Mr Lawton, said Cheshire Constabulary.
Mrs Lawton raised the alarm when her husband failed to cross the finishing line in the Taygetos Challenge.
Mr Lawton passed the fourth checkpoint on the mountain trail but did not reach the fifth checkpoint, said the race organisers.
Steve Lawton, also a keen marathon runner, has retraced his father's steps on the route in a bid to trace his father who is a member of Sandbach Striders running club.
He said: "We are increasingly concerned for my father's safety and it is vitally important that we maintain the momentum of the search."
The British Embassy in Athens has been informed of the incident,
A posting on the Sandbach Striders website read: "John Lawton, a popular and well-respected member of Sandbach Striders, has not been seen since Sunday 8th of April when he ran in the Taygetos Challenge 2012, near Kalamata.
"As each Strider will already know, John is a highly experienced off-road and marathon runner. It goes without saying that we are all deeply concerned about him at this time and our thoughts are with his wife Lynda and his family.
"We are all hoping and praying that we have some good news to report very soon."
Anyone with any information in relation to Mr Lawton's whereabouts can contact Cheshire Police on 101 quoting incident 960 of April 13.