COPENHAGEN, Denmark -- The Danish inventor suspected in the death of a Swedish journalist who went on a trip on his home-made submarine has told a pre-trial custody hearing that she died after she was accidentally hit by a heavy hatch in the submarine's tower.

Peter Madsen said 30-year-old Kim Wall then dropped to the floor and bled from an open skull fracture.

Madsen told the court he slipped when in the tower and tried to hold the hatch, but it fell down. The journalist, who was on her way up the tower, was hit in the head by the 155-pound hatch and bled from an open skull fracture, he said.

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He explained the accident horrified him and that he hauled Wall up using a rope, which resulted in her clothes being pulled off. He then dropped her body into the sea and intended to commit suicide.

Wall, 30, disappeared during an outing on Madsen's submarine on Aug. 10. Her naked torso was found off Copenhagen last month. Police say her head, arms and legs had been deliberately cut off and have not been found.

Madsen was arrested Aug. 11 and had been detained on preliminary charges of manslaughter and indecent handling of a corpse.

Tuesday's hearing was not aimed at determining Madsen's guilt, but rather whether there was sufficient evidence to maintain his detention as police investigate. Madsen appeared calm in court, though irritated by the prosecution, which says the suspect is changing his explanation of the event as more information comes to light.

A Danish judge extended his detention during the hearing.