Psychiatric assessment may also be made of Madsen as the prosecution builds its case, Danish broadcaster TV2 reported on Thursday.
The 46-year-old has been held in custody since August 11th. He was initially detained for 24 days on preliminary manslaughter charges by Copenhagen City Court.
Prosecutors have until September 5th to request an extension of his custody.
"At the latest on September 5th, we will try to hold him in custody on a murder charge ... after her (dismembered) body was found," special prosecutor Jakob Buch-Jepsen told AFP, referring to Peter Madsen.
Madsen, who denies the accusations, claimed immediately after his rescue from the sunken submarine that 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”.
The new explanation was kept behind closed doors by the court until Monday this week.
Lead investigator Jens Møller Jensen said at a press briefing at Copenhagen's Politigården police headquarters on Wednesday morning that it appeared Wall's body had been tampered with to make it sink.
“With regard to the autopsy, I can add that there are some injuries to the torso that appear to have been caused deliberately in an attempt to ensure that air leaves the body to prevent it from floating or leaving the sea bed.”
“Similarly, metal was attached to the body, ostensibly to make sure that it sank to the bottom,” Jensen said.
This constitutes evidence that can be used by the prosecution when the court next meets to discuss extending Madsen's detainment, Buch-Jepsen told TV2.
“It is natural that we will present the new evidence to the court no later than September 5th, in relation to the Court's assessment of the basis for imprisonment,” he said.
This means that the prosecution could seek to have Madsen's detainment extended on suspicion of intentional killing, writes TV2.
Further relevant evidence is includes the police conclusion that the UC3 Nautilus was sunk deliberately shortly after it was found in Køge Bay on August 11th.
Police have also taken DNA samples from Madsen and are investigating communication between Madsen, Wall and relevant third parties. Additionally, prosecutors will charge Madsen with improper conduct relating to a corpse, according to the report.
Wall's torso, which was found near the shore on the island of Amager on Monday, had its arms, legs and head "deliberately" removed, police said on Tuesday.
On Thursday, police released the information that the body had been found without clothes – and that they were still searching for the items Wall was wearing on the evening of her disappearance.
“We are looking for a bright orange shirt, a black and white flower-patterned skirt and a pair of white shoes,” Danish news agency Ritzau reported Jensen as saying.
Buch-Jepsen told TV2 that it would be “natural” to request the court for an evaluation of Madsen's psychiatric condition to be carried out.