Russia on Wednesday investigated the death of a 27-year-old man in a giant \"zorb\" ball that tumbled down a mountainside in a horrific accident that was caught on video. Denis Burakov, 27, died of his injuries after he and a friend, Vladimir Shcherbov, 33, paid to roll together in the zorb down an unfenced snow slope at a ski resort in the Karachayevo-Cherkessia region of the North Caucasus. \"We have launched a criminal case into causing death through providing unsafe services,\" said Sergei Shuvayev, spokesman for the regional investigative committee. The charge carries a maximum prison sentence of six years. Investigators on Wednesday afternoon detained a 25-year-old local man, Ravil Chekunov, who was one of the ride\'s organisers, Shuvayev told AFP. \"They are questioning him now,\" Shuvayev said. Chekunov will probably appear in court on Thursday to extend his detention, he added. Zorbing is an extreme adventure sport invented in New Zealand in the 1990s in which participants roll down slopes strapped inside large transparent plastic balls. Deaths from zorbing accidents are very rare. During the January 3 accident, the zorb with the two men veered off a snowy track down the 3,000-metre-high Mussa-Achitaro peak and rolled into a gorge, continuing for around a kilometre before stopping on a frozen lake, investigators said. \"As a result of the fall, Burakov died of his injuries, while Shcherbov was hospitalised with serious injuries,\" investigators said in a statement. Burakov died after suffering injuries to his spine, heart, lungs and brain, investigators said, citing a pathologist\'s report. Survivor Shcherbov suffered a concussion and numerous cuts and bruises. \"He is in a serious state but his life is not in danger,\" Shuvayev told AFP. The two men from the southern Russian city of Pyatigorsk had come to the Dombai ski resort on January 1 to spend time snowboarding, the government daily Rossiiskaya Gazeta reported. The organisers did not have a licence, and the deadly ride was the first time they had sent down the zorb with people inside, Russian television reported. \"This ride was organised illegally. At this height, in a high mountainous place, it is categorically prohibited to organise and hold such an event,\" Shuvayev said in televised comments. The emergency situations minister Vladimir Puchkov, whose country will host the 2014 Winter Olympics, responded Wednesday by ordering fresh safety checks on winter sports venues. \"I want to draw your attention to a number of serious, tragic events at places where people relax and do winter sports. I am asking the relevant officials to send down firemen and rescuers again to ensure that these places are safe and screened off.\" The inventors of zorbing, Zorb Ltd, issued a statement Wednesday saying they were \"distressed\" by the accident but said the Russian ride was run by an illegal operator and the equipment was not manufactured by Zorb Ltd. Having two men in the same sphere presents \"clear and obvious dangers,\" the company said, as does operating in mountainous, rocky and snowy conditions. \"This accident was completely avoidable.\" In a video of the incident posted on the Internet, those watching the zorb ride initially laugh as the sphere veers off the track. When the ball starts tumbling down the jagged mountainside and into the gorge, they can be heard asking organisers: \"What is down there?\" \"A catastrophe,\" one replies.