The man accused of one of Denmark's most gruesome and horrific murders will go on trial today.

Danish inventor Peter Madsen will appear at Copenhagen City Court, accused of killing 30-year-old Swedish journalist Kim Wall.

Her death last summer shocked the nation.

Over the course of the 12-day trial, further horrific details are expected to emerge of the circumstances surrounding the case.

:: Kim Wall murder trial: What you need to know


Ms Wall disappeared in August last year after boarding Mr Madsen's self-built submarine.

Image: Kim Wall was a well-known and award-winning journalist when she died

She had shown an interest in his work and wanted to write a story about him.

As an award-winning freelance reporter, her work had appeared in publications including The Guardian, The New York Times, Atlantic and Time Magazine.

Mr Madsen is a minor celebrity in Denmark, known for his eccentric engineering projects. He has built rockets and submarines and hoped to become the first Dane to propel himself into space in a home-made rocket.

On the evening of 10 August, Ms Wall met Mr Madsen on the quayside in the Revshaleoen area of Copenhagen after he had granted her an interview and a trip on his submarine. She had told her boyfriend that she would be a few hours.

By the early hours, however, she had not returned.

The following morning, a large search was launched. No distress signal had been issued by the submarine but hours later it was spotted sinking in a bay south of the capital.

Mr Madsen was picked up but there was no sign of Ms Wall.

He claimed that he had returned with her to Revshaleoen the previous evening as planned and that he had then headed out again, alone, when the boat suffered a fault causing it to sink.

But he changed his story when questioned by police, claiming that she had died in an accident on board after hitting her head on the submarine's hatch.

Image: In the weeks following Ms Wall's disappearance, various body parts washed up

Eleven days after she went missing, however, the discovery of a torso along the shoreline near where the submarine went down was the first clue to what might have happened on board the vessel.

Over the subsequent weeks various body parts washed up - they had been weighed down.

Pathologists could not conclude how she had died, but did rule out a head injury.

In questioning, he then admitted he had dismembered Ms Wall's body, but he did not explain how she had died.

According to the prosecution's official indictment, he cut and stabbed her multiple times before killing her and dismembering her body.

Her body parts, the indictment said, were weighed down and thrown into the sea.

Image: This photo shows Ms Wall standing in the submarine UC3 Nautilus

Mr Madsen has been charged with premeditated murder, indecent handling of a corpse and "sexual relations other than intercourse of a particularly dangerous nature".

A post-mortem examination of Ms Wall's remains found evidence that she had been stabbed multiple times in her genitals.

But speaking to Sky News, retired Danish judge and professor of criminology Eva Smith explained that the prosecution will need to prove that she died in a premeditated murder.

"It's up to the prosecution to prove beyond reasonable doubt that he did murder and he had planned to do so.

"Nobody is guilty until the court has decided so, so the indictment is saying that this was premeditated, in other words, he had planned to do this.

"So this is for the prosecution to prove and so far we don't know how they will go about doing that," Mrs Smith said.

"It may not be too hard to prove that he killed her but that it was premeditated may be a challenge for the prosecution.

"He has changed his story a lot of times but he has not admitted to having killed her.

"He has not admitted to killing her on purpose," she said.

"He is still claiming it is some sort of accident."

Image: The submarine is sitting under a tarpaulin in the corner of an industrial estate

The submarine where Kim Wall died is now sitting under a snow-covered tarpaulin in the corner of an industrial estate on the city's outskirts.

Only Peter Madsen knows the truth about what happened inside.

The trial will sit over 12 days between now and the end of April.

It will be required to examine all the horrific details surrounding her death.

But it is her life and her legacy as a young female journalist that her family is determined to remember.

Her mother Ingrid said: "We will let her soul and spirit live on and we will do that through the Kim Wall Memorial Fund.

"That will help other young journalists to keep up the good work in Kim's spirit. That, we owe her."