The vessel is being scanned using technology from Danish tax agency Skat, police confirmed in a press statement on Tuesday.
Police said that they could not rule out the possibility of hidden compartments existing on board the sub.
“The scan is taking place on the basis of many different reports on possible cavities, on submarines in general and also in relation to Nautilus,” police wrote in a press statement.
Scanners usually employed by the tax authority to investigate containers for smuggled contraband will be used to investigate the submarine.
“We are searching, in relation to the nature of the case, for evidence of a crime as well as potential weapons and so on. We stress that the scan is being conducted to rule out the presence of undiscovered compartments, and not on the basis of specific suspicions of this,” the statement continued.
Police are also continuing their ongoing search for parts of Wall’s body that are yet to be recovered using Swedish tracking dogs that are trained to search in water.
Searches carried out by aircraft earlier this week failed to yield further leads in the case.
The police prosecution announced via a press statement on Friday last week that charges against Peter Madsen, the owner of the submarine, had been extended.
46-year-old Madsen has been held in custody since August 11th. He was initially detained for 24 days on preliminary manslaughter charges by Copenhagen City Court.
The submarine owner claimed immediately after his rescue he had brought Wall back to land at around 10.30pm on the night of her disappearance.
He changed his story the following day, telling Copenhagen City Court on August 12th that he had buried Wall at sea after she died on board due to an “accident”.
Wall’s torso was found at the shore on the island of Amager next to Copenhagen on August 21st.
Madsen denies both mutilating a corpse and killing Wall.