The man departed with journalist Kim Wall on his submarine before it sank, but she remains missing.
A Danish submarine owner has appeared in court over the disappearance of a Swedish female journalist who had been on board his vessel before it sank.
Peter Madsen, 46, denies wrongdoing, saying he had dropped off the reporter – 30-year-old Kim Wall – in Copenhagen before the sinking.
Her partner raised the alarm in the early hours of Friday when she failed to return from the Nautilus vessel.
It was later spotted but sank on Friday morning and Mr Madsen was rescued.
Police have launched a search for Ms Wall, a freelance journalist based in New York and China who has written for the New York Times, the Guardian and Vice Magazine.
Danish media said Mr Madsen had been charged with negligent manslaughter and would be detained for 24 days, following his court appearance on Saturday.
Police would not comment on why charges had been brought before a body had been found.
In a statement to Swedish paper Aftonbladet, Ms Wall’s family said: “It is with great dismay we received the message that Kim is missing. We believe and sincerely hope she will be found safe and well.”
Her friends and family have been posting widely on social media asking for her whereabouts.
Salvage teams started raising the Nautilus from the seabed in Koge Bay, south of Copenhagen, on Saturday.
Police are hunting for witnesses and camera footage to determine whether the missing woman had disembarked after setting off.
Footage aired by Denmark’s TV2 shows Mr Madsen getting out of what appeared to be a private boat, giving reporters a thumbs-up sign, saying: “I am fine, but sad because Nautilus went down.”
He later told a reporter: “I was out on a rehearsal trip, tinkering with different things in the submarine. Then a defect happened with a ballast tank which wasn’t that serious – until I tried to repair it – then it suddenly became very serious.
“After that it took 30 seconds for Nautilus to sink. I couldn’t close the hatch or anything. But that might be OK, as I would still be down there then.”
Ms Wall had been writing about Mr Madsen and his submarine, which at one stage was the largest privately-made vessel of its kind.
Mr Madsen made headlines in 2008 when he built the home-made submarine, that is almost 18 metres long, by using online crowd-funding.
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