A Danish aerospace startup founder has been accused of killing a journalist and sinking his own submarine

Peter Madsen aboard the UC3 Nautlius. Picture: Frumperino/Wikimedia Commons

The co-founder of aerospace startup Copenhagen Suborbitals, Peter Madsen, has been arrested and held over the death of 30-year-old journalist Kim Wall.

Madsen left the non-profit spaceflight organisation in 2014, but is perhaps better known as the owner of the 18-metre UC3 Nautilus, once the largest privately owned submarine in the world.

He built it with the help of crowdfunders over three years, and apart from a now-resolved wrangle with Copenhagen Suborbitals over whether he or the startup owned the vessel, has operated it relatively trouble-free.

Until last week, when he was seen boarding the vessel with Wall on Thursday and setting sail from the Refshaleøen island harbour near Copenhagen.

A cruise ship reported the vessel’s movements to military authorities soon after, but at 2.30am Friday, Wall’s partner reported her missing.

By mid-morning Friday, the Danish Defence Force had found the Nautilus, but after contacting Madsen, they were told it had “technical issues”.

Soon after, Madsen was rescued, but there was no sign of Wall. By Friday evening, Madsen had been charged in relation to Wall’s death. He then claims the submarine sank in seven metres of water due to “stabilisation issues”.

“I am fine, but sad because Nautilus went down,” Madsen told Denmark’s TV2. “A minor problem with a ballast tank… turned into a major issue.”

Madsen claimed he dropped Wall off on the Refshaleøen island just before midnight Friday. The media storm that has followed the case over the weekend was therefore focused on what would be found when the sub was eventually raised.

This morning, police managed to board the submarine, but no body was found.

Copenhagen police homicide chief Jens Moller said it appeared the Nautilus had been intentionally sunk.

Madsen denies the allegations but will be held in custody for 24 days.

NOW WATCH: Tech Insider videos

Want to read a more in-depth view on the trends influencing Australian business and the global economy? BI / Research is designed to help executives and industry leaders understand the major challenges and opportunities for industry, technology, strategy and the economy in the future. Sign up for free at research.businessinsider.com.au.