Kim Wall, 30, was most recently seen on Thursday evening on board the vessel with the proprietor, 46-year-old Peter Madsen.
The submarine later sank and Mr Madsen was protected before being captured and accused of murder.
The stricken vessel, the Nautilus, has been raised yet no body was found and the look for Ms Wall goes on.
Mr Madsen at first said that he dropped Ms Wall off before it sank yet police say he has now changed his announcement – in spite of the fact that they have not said what to.
Who is DIY submariner Peter Madsen?
Police gave no other data on why they thought the Nautilus was purposely sunk, however it negates Mr Madsen’s clarification that there was a specialized blame.
Mr Madsen has denied association in Ms Wall’s passing, and will be held in guardianship for 24 days while examinations proceed.
Ms Wall’s sweetheart initially announced her missing after she neglected to come back from what ought to have been a short stumble on the submarine.
She had been expounding on Mr Madsen and his submarine, which at one phase was the biggest secretly made vessel of its kind.
Police are as yet engaging for witnesses who may have seen Ms Wall on Thursday evening.
“Regardless we’re trusting that we’ll discover Kim Wall alive, yet we are setting ourselves up for the way that she may not be,” Copenhagen police crime boss Jens Moller said.