Danish inventor Peter Madsen has been found guilty of the mutilation and murder of Swedish journalist Kim Wall, and sentenced to life in prison.

He was also found guilty of the indecent handling of a corpse and "sexual relations other than intercourse of a particularly dangerous nature," evidenced by stab wounds inside and outside Wall's genital area.

Wall, a promising 30-year-old journalist, was last seen boarding Madsen's submarine in Copenhagen on August 10 last year when she had planned to interview him for an upcoming article.

Instead she disappeared, her torso washed up on August 21 on an island near Copenhagen. Her head and legs were found weeks later.

Madsen consistently denied charges of murder and sexual assault, claiming Wall died by accident from carbon dioxide poisoning, although he admitted to dismembering her body and tossing it into the sea in a state of panic.

Asked on Monday if he wanted to make a last statement before the jury went into deliberation, he said, "If anything, I am sorry about what happened."