An “outgoing and bubbly” university graduate fell to his death from a cliff near a Swiss ski resort after drinking with friends, an inquest heard.

The body of Jonathan Myles Robinson – known to friends and family as Myles – went undiscovered for six days following his disappearance on December 22, 2009.

The post-mortem examination by Swiss officials confirmed the keen skier had been drinking alcohol the night he went missing - and found traces of a designer amphetamine in his system.

However, Nathaniel Carey, who conducted a second post-mortem report in the UK, told Westminster Coroner’s Court on Wednesday a lack of analysis into these traces made it hard to know whether they were “relevant”.

While many explanations as to how the 23-year-old, of Gorst Road, Battersea, came to fall from a 330ft cliff, it was likely his death was accidental, the court heard.

The Chelsea FC fan, who had just completed an economics and business management degree at Newcastle University, had been eating dinner with family and friends on December 21, when a group of them decided to visit some bars near Wengen, Switzerland.

At about 2.20am the following morning, Mr Robinson walked friend Amy O’Brien back to her hotel but, after the pair said their goodbyes, subsequently disappeared.

In the days that followed, police-led and private search parties scoured the area around the resort - and his disappearance made national news in the UK.

However, on December 28, his body was found in a wooded area at the foot of the Steinhalten/Mönchsblick, a cliff above Lauterbrunnen.

During the inquest, coroner Paul Knapman said a Swiss toxicology report recorded his blood alcohol level as being the equivalent of 2.5 times the drink drive limit.

Dr Nathaniel Carey said it was likely Mr Robinson’s mobility would have been affected by drink as he walked along the treacherous mountain path.

Dr Carey revealed he found multiple internal and external injuries, describing them as “the kind you would expect from a substantial fall from height”.

He said, while he could not rule out any kind of foul-play, the available evidence “does not point to that”.

Detective Superintendent Jill Bailey, who led a Metropolitan Police investigation into the incident, said: “The only thing that’s known in this scenario is there’s a distinct lack of information to point us in any direction whatsoever.”

However, she agreed it was unlikely Mr Robinson was the victim of a crime or committed suicide.

She added: “One of the search teams did go to the top of that area and found it to be particularly icy and dangerous and they had to use ropes to secure themselves while they searched it.”

Dr Knapman said: “We are left with a likely explanation of him wandering out under the influence of alcohol on a presumably starry night for a walk, uninhibited by the effects of alcohol and then for whatever reason, simply by walking or tumbling or stumbling, coming off the cliff.

“The most likely explanation is an accident but other possibilities have not been excluded.

“This is a terrible tragedy of a young man with every expectation of a happy and successful future in front of him dying suddenly in these circumstances.”

Accepting Mr Robinson died of multiple injuries, he added: “How he came to be there and how he came to fall is not clear and I record an open verdict in this case.”

Speaking outside court, Mr Robinson’s older sister, Cara, said her brother was “a really outgoing, bubbly, lovely, sporty and a fun guy to be around”.

Responding to Dr Knapman’s ruling, she added: “I totally agree with everything he said – I understand how it has to be an open verdict.”

His father, Michael, said: “I think an open verdict is probably all he could do.”

Mum Sarah spoke of the Myles Robinson Memorial Trust, which has been established to support charities that enable young British people to travel overseas to help children in developing countries through teaching and sports coaching.

The trust, which the family believe is a fitting way to build on the work that Mr Robinson did in Ghana teaching football during his gap year, was set up with Partners Capital – the company the 23-year-old was due to start work for in 2010.

For more information visit mylesrobinson.co.uk.

• Pay your tribute to Mr Robinson by emailing imason@london.newsquest.co.uk or leave a comment below.