A father-of-two has been killed after the giant inflatable ball (known as a "zorb") he was riding in suddenly veered off course and plunged down a mountainside.
The terrifying ride which saw Denis Burakov lose his life, was captured on video as it unfolded in the Dombai ski resort in the Caucasus Mountains of southern Russia, the Associated Press reported.
His friend Vladimir Shcherbako was in the zorb with him and was badly injured in the accident.
According to investigators, the zorb veered off track and rolled into a gorge, rolling for around a kilometre before stopping on a frozen lake.
Police commander Sergei Shuvayev told AFP a criminal case into causing death through providing unsafe services had been launched.
Shcherbako remains in hospital "in a serious state, but his life is not in danger", Shuvayev said.
Burakov is thought to have broken his neck and his spine before being ejected from the ball and landing in the snow.
He was found alive but died on the way to hospital, The Mirror said.
The stunt was captured on a camera phone by a friend, who is heard telling Burakov as he climbs in: "Denis, you'll be like Jackie Chan in the Armour of God movie!"
As the ball veers off course however, a man's voice can be heard shouting "Oh fuck, it's gone in the wrong direction again" before screaming 'hold it, hold it! hold!"
He then adds: "Ah well, it's OK, it'll stop by itself."
Sergei Loginov, deputy director of Russia's largest supplier of zorbs told the Associated Press the run that killed Burakov was conducted in violation of all safety rules.
He said: "It's not even irresponsibility. it's an experiment on life. It's all or nothing. They either survive or they don't."
A website called Zorb Scams warns against zorb operators who do not utilise track and safety barriers down the hill. It also points out safe zorb operators will not run along next to the globe as it's moving.
Zorbing is a popular sport which sees participants roll downhill in an orb, generally made of transparent plastic.