COPENHAGEN, Denmark -- Danish submarine inventor Peter Madsen, convicted of torturing and murdering Swedish reporter Kim Wall last year, lost his appeal against his life sentence Wednesday, shortly after he apologized to the victim's family. The 47-year-old listened quietly as judge Jan Uffe Rasmussen read the ruling by the Eastern High Court.

Rasmussen said the high court had reached the same conclusion as the Copenhagen City Court, which sentenced Madsen to life in April after convicting him of murder.

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

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The prosecutor had argued that the life sentence should be upheld, saying the motive was sexual and the crime was planned.

"I'm terribly sorry to Kim's relatives for what happened," Madsen told the panel of judges as he was given the last word.

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

Defending Madsen, lawyer Betina Hald Engmark argued that her client "has a clean criminal record and alone has been convicted for one murder."

"In comparable cases, the perpetrator often has committed moral crimes before," she said.

This photo shows allegedly Swedish journalist Kim Wall standing in the tower of the private submarine "UC3 Nautilus" on August 10, 2017 in Copenhagen Harbor. Getty

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

The Copenhagen City Court in April convicted Madsen 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."

Kirk said violent videos in which women were tortured and killed were found on Madsen's computer, and said he likely filmed the killing. He added Madsen had been planning the murder and "just waited for a victim."

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

No video of Wall's murder has been found.

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

The cause of Wall's death has never been established.