A prominent digital entrepreneur says thieves made off with "several dozen million euros in bitcoin" after robbing his flat in Madrid, Spanish media reported on Wednesday.
The victim, whom the Spanish press has identified as the founder of the social network Tuenti, Zaryn Dentzel, says the robbers tortured him for four hours, forcing him to reveal the passwords for his digital assets.
Four or five people rang the man's doorbell and forced entry when he opened the door.
Spanish police confirmed the veracity of the media reports. The criminals are suspected to have come from Eastern Europe. However, investigators are pursuing all possible avenues, a spokesman said.
The heist took place on Tuesday, in a luxury apartment complex near the Prado Museum in the centre of the Spanish capital. The victim was a US citizen, aged 38, from Santa Barbara, California, who has lived in Spain since the late 1990s.
Laptops, tablets, mobiles
Two other men - a friend and a handyman - were in the apartment at the time of the robbery, according to the victim's statement. Both of them were reportedly bound and gagged.
The man said the thieves attacked him with a taser, carved into his chest with a knife and sprayed something in his eyes. Laptops, tablets and mobile phones are said to have been taken.
According to media reports, there are witnesses to the crime. One neighbour reportedly said that he saw a group of men, faces covered, carrying several large bags as they left the building.