Inventor Peter Madsen poses in front of his UC3 Nautilus submarine in Copenhagen, Denmark. Picture: Niels Hougaard/Ritzau via AP

Copenhagen, Denmark - Danish submarine inventor Peter Madsen, convicted of torturing and murdering Swedish reporter Kim Wall last year, appeared in court Wednesday on the last day of his appeal against a life sentence.

Closing remarks had been adjourned September 14 after a juror collapsed. The hearing resumed Wednesday.

Madsen, in a dark blazer, black T-shirt and grey pants, listened quietly at the Eastern High Court where the prosecutor demanded life, saying the motive was sexual and the crime was planned.

In Denmark, a life sentence is on average 16 years but can be extended if necessary. Madsen, 47, wants a time-limited sentence, not an open-ended prison term.

It is unclear when the verdict will be announced.

Madsen denies murdering Wall, saying she died accidentally inside the submarine, but has confessed to throwing her body parts into the Baltic Sea.

Prosecutor Kristian Kirk talks to the media as he arrives at the Eastern High Court in Copenhagen. Picture: Liselotte Sabroe/Ritzau Scanpix via AP

On April 25, Madsen was found guilty by the Copenhagen City Court of murder, sexual assault and the dismembering of Wall. The court ruled unanimously that Madsen had lured Wall, 30, onto his home-made submarine with the promise of an interview.

Prosecutor Kristian Kirk said Wall could not escape and "likely had begged for her life" while Madsen carried out "a sadistic, yes inhuman, sexual fantasy," and Madsen had been planning the murder and "just waited for a victim."

"I hope we never will see such a case again," Kirk told the court.

Madsen had a sadistic interest in so-called snuff videos where women are tortured and killed, and he likely filmed the killing, Kirk said.

Defence attorney Betina Hald Engmark arrives at the Eastern High Court in Copenhagen. Picture: Liselotte Sabroe/Ritzau Scanpix via AP

No video of Wall's murder has been found. Kirk said snuff videos which Madsen had not produced himself had been found on his personal computer.

"Kim Wall walked directly into a death trap," Kirk said before looking up at Madsen who listened with his hands folded on the table: "I cannot see any other sentence than life."

The cause of death has never been established.

Ingrid and Joachim Wall, the reporter's parents, were present in court.