Swedish journalist who died on an inventor's submarine had 15 stab wounds

A post-mortem has revealed a number of stab wounds to Kim Walls body. Photo / AP

A Danish inventor charged with murdering Swedish journalist Kim Wall in his home-made submarine had video footage on his computer showing women being violently killed, a court heard yesterday.

A police prosecutor said officers found images "which we presume to be real" of women being strangled and decapitated on the hard drive on Peter Madsen's computer in a laboratory he ran.

That, together with new post-mortem evidence showing Wall was stabbed 15 times in her ribcage and genitals 'around or shortly after her death,' was adding to the case against Madsen, the prosecutor, Jakob Buch-Jepsen, told the Copenhagen court.

This photo allegedly shows Swedish journalist Kim Wall standing in the tower of the private submarine UC3 Nautilus on August 10, 2017 in Copenhagen Harbour. It was the last time she was seen alive.

DNA tests from Madsen's nails, face and neck showed a clear match with Wall's, Buch-Jepsen said, though the exact cause of death remained unknown.

"Our suspicion hasn't changed, it has been strengthened since (the last hearing on) September 5," he added.

Madsen, who denies murdering Wall and another charge of mutilating her body, appeared in court via video link dressed in a green boilersuit.

In this undated photo, designer Peter Madsen looks on in Bornholm, Denmark. Photo / Getty

The privately owned submarine, Nautilus, which is the suspected crime scene for the assumed murder on Swedish journalist Kim Wall, is carried out of Copenhagen harbour. Photo / Getty

He said the computer searched by police was not his.

"They are the space laboratory's tools which have been used by everyone in the laboratory," he said.

The court heard he had been working on building a space rocket in the lab.

He remained calm during the pre-trial session, sitting with his hands folded most of the time. The court ordered him detained for another four months as investigations continued.

Prosecutor Jakob Buch-Jepsen addresses the media in front of the District Court of Copenhagen yesterday. Photo / AP

Wall, a 30-year-old freelance journalist who was researching a story on Madsen, went missing after he took her out to sea in the 17-metre craft in August.

Madsen has told the court in past hearings Wall died accidentally, saying she was hit by a heavy hatch cover on his UC3 Nautilus submarine.

On August 23, police identified a headless female torso washed ashore in Copenhagen as Wall's.

Madsen has also denied amputating her limbs, saying he tried to bury her whole body at sea.