Norwegian mass killer Anders Behring Breivik, seen at court in Skien prison, in March 2016
Oslo (AFP) - A Norway court on Tuesday begins examining the state's appeal against a ruling that it has treated mass murderer Anders Behring Breivik "inhumanely" since he was jailed for killing 77 people in 2011.
Last April, a district court in Oslo delivered a humiliating blow when it concluded the 37-year-old rightwing extremist's rights had been violated and he was subjected to "inhumane" and "degrading" treatment in prison.
Norway prides itself on having scrupulously respected the rule of law after the country suffered the bloodiest attack on its soil since the end of World War II.
Stunned, the state appealed against the ruling.
On July 22, 2011, Breivik, disguised as a policeman, gunned down 69 people, most of them teenagers, at a Labour Party youth camp on the small island of Utoya, tracking them down for more than an hour where they were trapped by the freezing waters of the lake.
Earlier that day, he killed eight people with a bomb he detonated at the foot of government building in Oslo.
Now serving a 21-year prison sentence that can be extended as long as he is considered a threat, Breivik has a three-cell complex where he can play video games and watch television on two sets. He also has a computer without internet access, gym machines, books and newspapers.
The district court judge ruled however that his conditions violated Article 3 of the European Convention on Human Rights.
"The prohibition of inhumane and degrading treatment represents a fundamental value in a democratic society ... (and) applies no matter what, (even) in the treatment of terrorists and killers," judge Helen Andenaes Sekulic wrote in her verdict.
Breivik's isolation is the main issue in the case.
He is held apart from other inmates for security reasons, and without enough social activities, according to the district court.
In five-and-a-half years, he has only been allowed contact with guards and other professionals such as lawyers and doctors, behind a glass pane, with the exception of one brief visit from his mother just before she died.
The lower court ruling also questioned the many potentially "humiliating" strip searches, the systematic use of handcuffs, and frequent awakenings at night, especially in the early days of his imprisonment.
The new six-day hearing risks opening up old wounds in Norway, as Breivik's previous court appearances have been marked by controversy and provocation.
During the lower court hearing, he arrived in court making a Nazi salute, complained about cold coffee and frozen meals, and compared himself to Nelson Mandela.
- Families prepared for 'the worst' -
While many in Norway try to ignore his stunts, a support group for families of the victims has warned its members to prepare for "the worst" -- meaning, another media frenzy.
Noting that Breivik had "among other things tried to knock out the legal system with his attacks", the group said the "best way to defend the rule of law was to apply its rules in this case like any other."
Breivik's state of mind is also expected to be debated vigorously during the hearing, which will be held, like the first one, in the gymnasium of the Skien prison where he is incarcerated, in southern Norway.
Some changes have been made to his prison conditions in recent months, including replacing a glass wall with a grill during his lawyer's visits and increased contact with guards.
His lawyer, Oystein Storrvik, insists however that "the state has not put in place concrete measures to remedy Breivik's mental vulnerability and damage due to prolonged isolation."
Attorney General Fredrik Sejersted has insisted "there is no evidence that Breivik is physically or mentally affected by his prison conditions."
The three appeals court judges are also to rule on an appeal by Breivik regarding his inability to freely communicate with the outside world.
On that point, the judge in April ruled in favour of the state, which closely monitors and filters the prisoner's correspondence to prevent him from forming a network capable of carrying out new attacks.
Breivik claims this violates his right to privacy, as guaranteed by Article 8 of the European Convention.