Hopes of finding a 79-year-old walker who went missing in mid Wales are fading - a week since he was last seen.

Philip Blake set off from Pandy near Abergavenny on a hiking trip along Offa's Dyke in the Black Mountains, on Monday, 13 May.

Mr Blake was last seen leaving his B&B

Police have now said they will not carry out any more searches unless there are positive sightings of him.

However, officers said they have not given up hope of finding him alive.

"Mountain rescue have spent a number of days up there in quite appalling conditions," said Sergeant Simon Deacy, Gwent Police.

"It's quite unfair to expect them to continue for what is, in effect, a needle in a haystack as far as that mountaineer is concerned."

"But they are available to go at a moment's notice if they get a new sighting and that is waht they will respond to now," he added.

Mr Blake is an experienced hiker and was wearing wet weather gear, but did not have any overnight camping equipment with him.

The walker from Herefordshire, was last seen wearing blue waterproof trousers, a tweed hat and carrying a rucksack.

The search was initially concentrated in the Hay Bluff area, but police then began searching places where he might have stayed.

We are talking about the whole of the eastern side of the Brecon Beacons National Park

Hugh Jones, Mountain rescue deputy team leader

On Saturday, more than 600 walkers helped rescuers on an extensive search of a 27 mile area.

But they found nothing.

Gwent Police have repeated appeals for local people to search sheds and garages for signs of Mr Blake.

On Friday, police earlier said the OAP made a call to a bed and breakfast on Monday morning to make a booking for that night but he never arrived.

Another walker has come forward to say that he spoke to Mr Blake on Monday afternoon but they split up and went in different directions.

Members of the Central Brecon Mountain Rescue Team began their search on Tuesday, focusing on a great swathe of the Brecon Beacons National Park.

Inspector Peter Davies: 'No sign'

Gwent Police Inspector Peter Davies said: "The search covered some 70km of footpaths but overall covered 44 square kilometres. Sadly, despite efforts Mr Blake was not located."

"The inquiry continues and we are now in the process of speaking to members of the public who believe they may have seen him."

Mountain rescue deputy team leader Hugh Jones told reporters they had been concentrating on the high footpaths, which were believed to be the main routes Mr Blake was taking, but the scale of the area was causing problems.

"We are talking about the whole of the eastern side of the Brecon Beacons National Park," he said.