A Danish inventor and entrepreneur was arrested Friday on suspicion of killing a Swedish journalist who had accompanied him on a ride on his submarine.
Peter Madsen, 46, was rescued in a Danish military operation after his submarine did not return from an excursion at its expected time, Copenhagen police said. Madsen had set off Thursday evening from Copenhagen's Refshale Island with the journalist, and around 3:30 a.m. Friday, authorities received a report that the submarine had not returned.
A rescue team later spotted the submarine in Køge Bay at 10:30 a.m. and made radio contact, police said. Madsen, who had gained fame in his home country for building the submarine, said he was heading into the harbor. About half an hour later, the submarine abruptly sank, police said.
Madsen was rescued by a private motorboat in the area, but the journalist was not found. Madsen told police that he had dropped her off Thursday not far from where the submarine journey began.
He is expected to appear before a judge on Saturday.
After his rescue, Madsen spoke to a Danish TV station about what happened. He didn't mention the journalist, and he said the sinking was due to issues with the submarine's ballast tank.
"I am fine, but sad because Nautilus went down," he told TV2, according to the Associated Press.
Divers have so far not been able to reach the submarine, police said. It is expected to be stabilized underwater or brought up and towed to land on Saturday.
Police are asking any witnesses to come forward who may have seen Madsen or the journalist on Thursday. She was not named by authorities, but friends on social media identified her as Kim Wall in posts hoping that she might still be found alive.
Wall had been writing about Madsen and his submarine and was reported missing by her boyfriend, Danish tabloid Ekstra Bladet reported. As part of the investigation, police are examining if Madsen sunk the submarine intentionally to hide evidence, it reported.
Madsen has for years been a colorful figure in Denmark. He launched his submarine, the Nautilus, in 2008. At the time, it was the largest privately built submarine in the world, and he completed it through volunteers and crowdfunding.
The self-styled "inventrepaneur" also co-founded an amateur rocket company.