For Griff Rhys Jones, it was a high point of his television career. He had scaled the tallest mountain in Britain, the cameras rolling all the while, and last night he learnt that he had won a coveted Scottish Bafta award for the resultant series, Mountain.

But even as the series was receiving the plaudits of the critics, doubts were beginning to surface in the climbing world. Mountain had won the category of Best Factual Entertainment Programme — but one mountaineering expert commented last night: “Entertainment, certainly — but factual?”

Did Rhys Jones actually get to the top of Ben Nevis? Or was this another of the BBC’s minor deceptions, along with all the other controversies such as fake phone-ins, the naming of the Blue Peter cat and the trailer that wrongly claimed to show the Queen storming out of a photo shoot?

The programme in question was broadcast in August, one of five in a series that showed Rhys Jones climbing in some of Britain’s most spectacular upland regions. It followed his repeated efforts to scale Ben Nevis, which is 1,343m (4406ft) above sea level.

It was dramatic stuff. He was shown making three attempts; first, in the company of some local athletes, then in hillwalking gear, then setting out for the summit, before retreating when the weather deteriorated. Rhys Jones described his third attempt as “unfinished business”.

Along with a guide, Mark Diggins, he tackled a rock scramble known as Ledge Route, which emerges on to a high plateau on Ben Nevis plateau, which has a cairn to mark it, but is not the summit.

It was here, in a voiceover recorded after the event, that Rhys Jones said: “I’ve made it to the summit of Britain’s highest mountain.” Later, in a book issued to accompany the series, he writes: “I had gone as high as I could in the country of Great Britain, and it felt excellent.”

But had he? The Ledge Route ends close to a separate peak known as Carn Dearg North West, which, at 1,214m, is 129m lower than the Ben Nevis summit, almost 2km away. The intervening terrain is rough, and indented by steep gullies, but has to be crossed by anyone claiming to have reached the top.

Asked about the discrepancy, a BBC spokesman said: “Griff climbed the Ben via the ‘Ledge’ route, up the north face. This brings you out at the Carn Dearg ‘top’ of Ben Nevis, on the summit plateau. We felt it would have been overly technical to explain to the viewer that Griff had reached a ‘top’ on the summit plateau, as, for the great majority of viewers, we are sure that to stand on the summit plateau at any of the tops would be the same as having reached the summit.

“When making this series for a broad-based BBC One audience, we have had to consider many issues of topographical detail like this. All these decisions are made in good spirit, and are intended to include, not to deceive.”

Not everyone agrees with the BBC’s assessment. “I feel that to have come out with such a whopper as Griff did on the programme is a slap in the face for the thousands who have struggled up the path to stand on the summit and feel the golden glow that a personal achievement provides,” said Ken Crocket, the respected climber and author of Ben Nevis: Britain’s Highest Mountain. “If I had succeeded in gaining the South Col on Everest, then been forced back down by either illness or weather, I would be open about it and not make any claim to have reached the summit. That might be on a different scale, but it would be the same lie.

“The weather on the day may have been damp, but it very obviously was pretty calm, so the conditions were not a problem. Perhaps Griff had a meeting to attend at sea level, perhaps a train to catch? I would have sympathised with him and accepted the outcome if he were open enough to admit that, while he reached the top of Carn Dearg, he certainly was well short of the highest point in the British Isles.”

Rhys Jones could not be contacted last night.

Aiming for the top

— Estimates vary as to how many people climb Ben Nevis each year, but the mix of regular hillwalkers, rock and ice-climbers tackling the north face, and ordinary tourists plodding up to the highpoint is believed to number about 100,000

— Most people aim for the summit, a distinctive place cluttered with an Ordnance Survey trig point, a bivouac shelter, a view indicator and the ruins of the summit observatory, abandoned in 1904

— There has been a long tradition of pedantry with regard to the location of Scottish summits. The differences can be substantial: the Ledge Route cairn, at 1,214m (3,983ft), is the same height as the summit of Ben Lawers, highest of the Perthshire hills but only the tenth-highest British hill overall

Source: Times Database

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