Copenhagen - Danish inventor and convicted murderer Peter Madsen's attempt to escape from prison was triggered by dissatisfaction with his conditions, his lawyer said on Wednesday.

"He believes that his rights to visits and communication opportunities during his incarceration have deteriorated, mainly due to who he his," Anders Larsen told reporters.

Larsen's remarks were made after a court hearing during which Madsen admitted that he had threatened prison staff and others during an attempt to escape from prison on Tuesday.

Madsen admitted to most of the six charges related to Tuesday's escape, including using a fake pistol to threaten a prison psychologist, several other prison staff members and the driver of a delivery van.

Police inspector Mogens Lauridsen attends a news conference in front of a police station in Albertslund, Denmark. Picture: Ritzau Scanpix/Mads Claus Rasmussen via Reuters

Madsen was quoted as telling the driver, "Drive, drive, drive - if you don't drive, I'll shoot you," news agency Ritzau reported.

However, Madsen denied receiving any assistance in his escape from the Herstedvester Prison, west of Copenhagen, Larsen said.

Most of Wednesday's hearing was held behind closed doors. The judge made that decision after prosecutor Rasmus Kim Petersen said Madsen had been helped by one or more accomplices who have yet to be identified.

The submarine UC3 Nautilus is seen covered with green tarpaulin in Nordhavn, in Copenhagen, Denmark, in 2018. Danish inventor Peter Madsen was sentenced to life in prison for torturing and murdering Swedish journalist Kim Wall on his private submarine. File picture: RITZAU SCANPIX/Mads Claus Rasmussen via Reuters

In order to prevent Madsen from harming the investigation, the court ordered that he be held on remand for 14 days.

The prosecutor said the police would be in charge of Madsen while he is on remand and "supervise his visits and correspondence."

Madsen was captured about five minutes after he fled from the prison. At the time of his arrest he was wearing what looked like a bomb belt.

Police officers are seen as Peter Madsen (not pictued) is surrounded by the police in Albertslund, Denmark. Picture: Ritzau Scanpix/Nils Meilvang via Reuters

A standoff ensued while explosives experts were summoned to the scene. Police later said they did not believe the belt had explosives.

In 2018, the 49-year-old was convicted of murdering Swedish journalist Kim Wall on his submarine in August 2017.

Madsen has denied murdering Wall, but has admitted to dismembering her body and dumping it at sea. He said Wall had died due to an accident.

During his previous trial, Madsen was represented by another lawyer. Larsen was drawn from a pool of lawyers, but said Maden had asked him to continue to represent him.