A court in Copenhagen heard on Friday that Danish inventor Peter Madsen — who is on trial for the murder of Swedish journalist Kim Wall — called himself a "psychopath, but a loving one."

A former associate of Madsen took the witness stand, describing how the engineer had a fascination with death and sexual fantasies.

"His sexual fantasies slowly got out of hand," the former co-worker at Madsen's laboratory told the court, adding that on two occasions he spoke about sex in relation to death.

Read more: Danish submarine murder suspect had 'torture videos'

Talk of snuff films

The associate said Madsen toyed with the idea of making a pornographic film showing acts of torture and was "interested in snuff films," or movies where a person is killed or kills themselves. He even suggested that she join in a sexual threesome or foursome.

Wall, who would have turned 31 on Friday, was last seen with Madsen on the evening of August 10 as his submarine left Copenhagen's harbor. She was due to interview him for a profile she was writing of him.

Her decapitated torso and other body parts were subsequently found, weighed down in plastic bags with metal objects, in the Bay of Koge, near the Danish capital.

Madsen is charged with premeditated murder, sexual assault, and desecration of a corpse, and could face up to life in prison if found guilty.

Story changed twice

Madsen is charged with premeditated murder, sexual assault, and desecration of a corpse over Wall's death

The 47-year-old initially told investigators that he had dropped Wall off at a restaurant where they had initially met. He later changed his story, telling police there had been a "terrible accident" on board, and a 70-kilogram (154-pound) hatch had fallen on Wall's head. In a panic, he had buried her body at sea, he said.

Later, he gave a third account of what happened, claiming Wall had died when the air pressure suddenly dropped and toxic fumes filled his vessel. At this point, he admitted dismembering her body and throwing it overboard. But he denies pre-meditated murder.

A cause of death has not been established.

Read more: Reporters Without Borders: 65 journalists killed worldwide in 2017

Intern paints another picture

The unnamed associate was one of several witnesses who appeared during day four of the trial.

One of Madsen's apprentice engineers described the inventor as a "kind, empathic, passionate man who was ready to listen," as opposed to media reports which suggested he had a "strong temperament."

Madsen is due to take the stand again on March 28, with around 35 witnesses to testify in the coming days.

Wall's parents — Joachim and Ingrid Wall — did not attend Friday's proceedings. Instead, they flew to New York for the presentation of a $5,000 (€4,000) grant created in Wall's name, the Kim Wall Memorial Fund.

The fund offers cash to ensure the safety of women journalists on reporting missions abroad.

mm/sms (AFP, dpa)

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