Breivik, a far-right extremist, killed 77 people in Norway's worst peacetime atrocity in July 2011.

He killed eight with a car bomb in Oslo and then gunned down 69, most of them teenagers, at a Labour Party youth camp.

Breivik, 42, is serving Norway's maximum sentence of 21 years, which can be extended indefinitely if he is deemed a continued threat to society.

The Telemark court in Skien, southwest of the capital, where Breivik is serving his sentence, will begin hearing the case on Tuesday after the Oslo state prosecutor's office last year rejected Breivik's application for early release.

"Our position is that it is necessary with (continued) confinement to protect society," the prosecutor in charge, Hulda Karlsdottir, told Reuters.

Proceedings will take place over a maximum of four days in a makeshift courtroom inside Skien prison, with a decision expected about a week later.

If Breivik's request is denied, Breivik, who has changed his legal name to Fjotolf Hansen, can apply for a new probation hearing in a year's time.

Breivik lost a human rights case in 2017 when an appeals court overturned the decision of a lower court that his near-isolation in a three-room cell was inhumane.

The European Court of Human Rights rejected a subsequent appeal

Some have raised concerns that he will use this week's court appearance to voice anti-Muslim sentiments.

"That will become apparent during the process, what he really wants to achieve," Breivik's lawyer Oeystein Storrvik told Reuters.

"He has asked to be released and that (request) is a right he has."

Australian Associated Press