Updated: 15.50

The Danish inventor found guilty of the "brutal" murder of Swedish journalist Kim Wall is to appeal the verdict and his life sentence.

Peter Madsen had denied killing the 30-year-old and insisted that she died accidentally during a visit to his home-made submarine at Copenhagen Harbour on August 10th last year.

But the 47-year-old repeatedly changed details of his story over the course of the 12-day trial spread over seven weeks.

Madsen initially claimed that he had dropped her off on the shore and he did not know what happened to her.

He then said she had died accidentally after hitting her head on the submarine's hatch, which led Madsen to bury her in the Baltic Sea.

When her remains were found on the seabed - including her head, which showed no signs of injury consistent with a blow to the skull - he instead claimed she had died of exhaust fume poisoning while he was outside on deck.

The forensic pathologist found no indication of such poisoning, exposing further inconsistencies in a defence that Judge Anette Burkoe described as "not credible and is not consistent with the following decision to dismember the body".

This article contains graphic details some readers may find distressing 

Madsen - a minor celebrity in Denmark - had admitted dismembering Ms Wall after she died, and told the court it was a "very, very traumatic event which I do not want to describe".

He later explained that he did it in order to be able to lift the body out through the UC3 Nautilus's narrow hatch, telling the court: "What do you do when you have a big problem? You divide it into something smaller."

Prosecutor Jakob Buch-Jepsen said Ms Wall's murder was "sexually motivated" and "premeditated" because Madsen brought along tools he normally did not take when sailing, including a saw and sharpened screwdrivers.

"There is no doubt that he murdered Kim Wall on purpose and that he had a sexual motive," the prosecutor said.

"It is uncertain whether Peter Madsen murdered Kim Wall by strangulation or cutting of the throat, but there is nothing that sows doubt about whether he killed Kim Wall on purpose."

Drawing by Anne Gyrite Schütt shows accused Peter Madsen (left) and the prosecutor Jakob Buch-Jepsen (standing right) on the first day of the trial at the courthouse in Copenhagen, Denmark | Imge: Anne Gyrite Sch'tt/AP/Press Association Images

Marks on her wrist and ankles showed she had been strapped to pipes inside the vessel, the prosecution alleged.

Mr Buch-Jensen also revealed the conclusion of a court-ordered psychiatric report on Madsen, which described the defendant being "intelligent, emotionally impaired with a severe lack of empathy, anger and guilt... and with psychopathic tendencies".

The prosecution showed images of her mutilated body and played a selection of more than 140 "snuff videos" found on Madsen's computer and iPhone which depicted the murder, torture, beheading and impalement of women.

He had decided to dismember and dispose of her body, he said, party because he had panicked and partly to spare Ms Wall's family of the knowledge that she had died of exhaust fumes.

However the forensic pathologist determined that some of Ms Wall's wounds were inflicted while she was alive or very shortly after she had died.

Madsen had said he dismembered her many hours later.

"He had fresh scratches on both forearms and dried blood under his left nostril. The blood belonged to Kim Wall," the prosecutor told the court.

Asked about the snuff videos on his computer, Madsen said it was no different from watching a horror film.

"It's as crazy as the movie you've seen, Seven. It's the same as films you've seen, Jakob." he said to the prosecutor.

Madsen's defence lawyer, Bettina Hale Engmark, has capitalised on the prosecution's inability to determine exactly how Ms Wall died.

Peter Madsen's submarine 'Nautilus' sits on dry land in Copenhagen, Denmark | Image: Theresa M?nch/DPA/PA Images

"It is not my client's duty to prove that he is innocent. It is the task of the prosecutor to prove that he is guilty," she told the court, arguing that the prosecution details were "not based on facts".

In summing up on Monday, the prosecutor told Copenhagen City Court that Madsen (47) should be given a life sentence, which is usually an average of 16 years in Denmark.

In addition to the murder charge, Madsen was also found guilty of sexual assault, of stabbing her in and around her genitals, and the abuse of a corpse.

Judge Burkoe said his crimes were "especially brutal" and Ms Wall's death was the result of a "cynical murder" of a journalist simply trying to do her job.

Ms Wall was a freelancer who had written for The Guardian, The New York Times, Vice and Time magazine - and she was attracted by offbeat, under-reported and quirky stories from around the world.

At the time of her murder, she was living with her boyfriend near Madsen's workshop in a disused Copenhagen shipyard, with his home-made submarine and quest to build a rocket capable of taking him to space making him an attractive subject for a story.

She had heard about the eccentric inventor and contacted him months earlier asking for an interview.

On August 10th last year he accepted the interview request and invited her aboard his submarine that evening.

Early the following morning, she had failed to return home and her boyfriend reported her missing.

Hours later, Mr Madsen was rescued from his sinking submarine in a bay south of the Danish capital. Ms Wall was not with him.

No date has been set for his appeal hearing.