Swedish journalist Kim Wall
A photo of Swedish journalist Kim Wall who was last seen aboard Peter Madsen's homemade UC3 Nautilus submarine TT NEWS AGENCY/ Tom Wall Handout via REUTERS

Videos of women being decapitated were found on the hard drive of a Danish inventor accused of murdering a journalist, prosecutors have said.

Peter Madsen's pre-trial heard that a hard drive found in his Copenhagen workshop contained footage of women being tortured, dismembered and burned.

Madsen charged with killing Kim Wall, 30, after the Swede boarded his home-made submarine on 10 August for an article on maverick engineers.

Her headless body was found in waters off Copenhagen 11 days later.

Madsen, who denies murder, said that the hard drive did not belong to him, and everyone in the laboratory where he worked had access to it.

"This hard drive doesn't belong to me," Madsen told a Copenhagen court.

"We had, among others, an intern living there," he added.

Madsen took part in the half-hour custody hearing with his lawyer via a video link from Copenhagen's Vestre prison.

Prosecutor Jakob Buch-Jepsen that Wall's cause of death had not yet been formally established, but that 15 knife wounds to her chest and genitals had been inflicted on her body "at the time of death or shortly afterwards".

Madsen claims Wall died after a 70kg hatch door fell on her — and he threw her intact body overboard in a panic.

The married 46-year-old said he then tried to bury her at sea and intended to commit suicide, sinking his submarine.

His defence lawyer, Betina Hald Engmark, said the court had heard "nothing that supports Kim Wall being killed by my client".

Wall was last seen alive on Madsen's UC3 Nautilus submarine on 10 August. Her boyfriend reported her missing later that day, and the 18-metre vessal was located south of Copenhagen the following morning.

Madsen, an entrepreneur, artist, submarine builder and self-taught aerospace engineer, was rescued just before the submarine sank, and arrested. He remains in custody and will appear in court again on 31 October.