After prison guards removed his handcuffs, he turned to journalists covering the hearing and stretched out his right arm in a Nazi salute. Stone-faced, he remained there for a few seconds as guards stood idle and his lawyer Oystein Storrvik nervously took a sip of water.
During his criminal trial four years ago, Breivik entered the court with his own salute, using a clenched fist instead of the outstretched hand that the Nazis used to greet Adolf Hitler. At the time Breivik described himself as a modern-day crusader, fighting to protect Norway and Europe from Muslim immigration.
In violence that shocked Norway on July 22, 2011, Breivik set off a bomb in Oslo's government district and then carried out a shooting massacre at the annual summer camp of the left-wing Labor Party's youth organization.
In letters sent to media from prison, Breivik said he has abandoned his armed struggle and now wants to create a fascist movement while serving his sentence.
Before the hearing started Tuesday, his lawyer, Oystein Storrvik, said the goal of the human rights case is to improve Breivik's prison conditions, including interaction with other prisoners and fewer restrictions on his mail correspondence.
Breivik is held as the only inmate in a high-security wing of Skien prison. He is allowed some mail correspondence but it is strictly controlled and he's not allowed to communicate with other right-wing extremists.
The government says the restrictions are well within the European Convention of Human Rights and are needed to make sure Breivik isn't able to build militant extremist networks from prison.
Follow CNBC International on Twitter and Facebook.