Danish submarine inventor Peter Madsen has admitted dismembering the body of Swedish journalist Kim Wall, whose body parts were found at sea after she interviewed him on board his homemade vessel, Danish police said.

In initial police questioning, Madsen had denied cutting up her body and said she died in an accident when a heavy submarine hatch fell on her head, but he has now changed his story to say she died of carbon monoxide poisoning while on board, police said in a statement.