Danish police announced Wednesday a headless torso that washed up from local waters matches the DNA of missing Swedish journalist Kim Wall.

The discovery, a “breakthrough” in the investigation, gives authorities a clearer picture of the reporter’s mysterious disappearance after she boarded a 55-foot privately built submarine on Aug. 10 for a story she was writing about the vessel’s inventor, Peter Madsen. Police believe Madsen intentionally sank the submarine off Denmark’s eastern coast the following day.

Danish inventor Peter Madsen is being held for involuntary manslaughter in the disappearance and apparent murder of journalist Kim Wall. (Niels Hougaard/Ritzau via AP)

Madsen, 46, now at the center of the shocking mystery, initially told investigators that Wall left the submarine, and disembarked on a northern Copenhagen island hours into their trip. But he later changed his story, saying in a statement Monday that Wall died following an onboard accident and he had “buried her at sea” at an unspecified location.

Swedish journalist Kim Wall, 30, disappeared after boarding Madsen's submarine, which later sank. A headless torso that washed up Monday matched Wall's DNA. (Tom Wall via AP)

Prosecutors said Thursday they are seeking murder charges for Madsen, the only suspect in Wall's death.

MURDER CHARGES SOUGHT FOR SUSPECT IN DEATH OF SWEDISH JOURNALIST KIM WALL

A torso was discovered Monday and DNA testing identified it as belonging to the 30-year-old journalist, said Copenhagen police chief Jens Møller Jensen at a press conference.

Police said the dismembered body was found attached to a piece of metal, “likely with the purpose to make it sink,” adding that the body had apparently been punctured to let air out before sinking it and Wall’s head, arms and legs had been “deliberately cut off.”

Madsen has been held since Aug. 11 on suspicion of manslaughter, and denies any involvement in Wall’s apparent murder. Prosecutor Jakob Buch-Jepsen told the B.T. tabloid that police expect to raise the preliminary charges against Danish inventor Peter Madsen, 46, to murder and indecent handling of corpse when he appears at a custody hearing Sept. 5.

Early life

Born in 1971, Madsen was raised with his three brothers by their father in a small town on the coast of Zealand, Denmark’s largest island. He told a biographer that his father, a carpenter, was abusive.

Madsen had an early affinity for science -- launching rockets in the schoolyard by the time he was just 15 years old, according to the biography, “Rocket Madsen: Denmark’s Do-It Yourself Astronaut,” written by Thomas Djursing.

“I loved the idea that a fully armed rocket stood behind the school,” Madsen told his biographer. “The school day was my countdown where I constantly looked at my watch thinking ‘T-minus-4 hours,’ ‘T-minus-3 hours,’ etc.”

Following grade school, Madsen began studying engineering at a university, but never completed his degree.

His ambitious visions and innovative inventions gained him public acclaim, propelling him to somewhat of a local celebrity and garnering him support from volunteers and investors.

Career in science

In 2008, Madsen co-founded Copenhagen Suborbitals, an amateur space exploration company. But before the organization successfully launched from a platform in the Baltic Sea in 2011, Madsen’s relationships with his partners had deteriorated, leaving him to continue his work alone.

DANISH POLICE: SUBMARINE OWNER SAYS WOMAN DIED IN ACCIDENT

Madsen is suspected of intentionally sinking the submarine he and Wall were in during the time of her disappearance, police said. (Niels Hougaard / Ritzau via AP)

In the biography, Djursing describes Madsen as a “one-man army,” earning a reputation as bad-tempered with a tendency to get frustrated with other engineers.

Madsen has been launching self-engineered submarines since 2002. He had brought other visitors on his third and latest submarine, the UC3 Nautilus -- the largest privately built submarine in the world, and the vessel from which Kim Wall disappeared.

"He's not a murderer"

After police announced Monday that Madsen changed his account of what happened to Wall, a colleague of Madsen’s spoke out.

In an interview with Danish tabloid newspaper BT, Jens Falkenberg, also a member of the amateur submarine building community, said, “Peter is a colorful personality, but he’s in no way evil, and I don’t believe there’s anything violent in him.”

“I can’t imagine Peter having killed her intentionally, but I can imagine an accident happening,” Falkenberg said. “The submarine is an ungainly place and you move around awkwardly. Perhaps she fell and broke her neck.”

“To me, Peter is not a murderer,” he said.

On Thursday, Denmark prosecutors said they plan to bring murder charges against Madsen.