Formal charges against a Danish inventor who admitted dismembering the body of a Swedish journalist aboard his submarine but denies killing her are likely to be laid in December.

Danish police in submarine investigation say they have found body parts including the head of journalist Kim Wall.

Police in Denmark are scanning the home-made submarine where a Swedish journalist was last seen alive, looking for any possible concealed cavities.

The Danish owner of a home-built submarine said a missing Swedish journalist died onboard in an accident and he buried her at sea in an unspecified location, according to police.