Breivik, 44, is serving 21 years in prison for killing 77 people in shootings and a bombing attack in Norway in 2011.

A neo-Nazi, Breivik killed 77 people, most of them teenagers, in shootings and a bombing attack in Norway’s worst peacetime atrocity in July 2011.

Breivik, now 44, is serving Norway’s longest sentence, 21 years, which can be extended if he is still considered a threat.

“He’s suing the state because he has been in an extreme isolation for 11 years, and has no contacts with other people except his guards,” Breivik’s lawyer Oeystein Storrvik told the Reuters news agency on Friday.

“He [Breivik] was moved to a new prison last year, and we hoped that there would be better conditions and that he could meet other people,” Storrvik added.

Norwegian daily Aftenposten was the first to report about the case earlier on Friday.

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

Last year, a Norwegian court also rejected his parole application, saying he still posed a risk of violence.

Storrvik said he expected the Oslo district court to hear the lawsuit next year.