By Gwladys Fouche and Terje Solsvik
OSLO (Reuters) - Convicted Norwegian mass murderer Anders Behring Breivik will sue to end his isolation in prison, arguing that such strict conditions violate his human rights, his lawyer said on Friday.
Breivik, who killed 77 people in a bomb attack and shooting spree, has been kept in solitary confinement since his arrest in 2011. Only prison staff, his lawyers and his mother, who died of cancer in 2013, have visited him in at least two prisons where he has been held.
His request should be heard in March next year and the Oslo district court has been asked to let him attend, lawyer Oeystein Storrvik said. Breivik's killing spree was the worst acts of violence committed in Norway since the World War Two.
"There will be a court case about his prison conditions," Storrvik told Reuters. "We are arguing that his prison conditions are a breach of human rights. He has been held in isolation for four years."
The court has not yet decided whether Breivik can attend, the lawyer said.
Breivik has previously complained that his prison conditions amounted to torture and threatened to go on hunger strike if they were not improved. Asked whether he would go ahead with this threat were he to lose the court case, Storrvik said: "We are focusing on the court case now."
Officials at the Skien prison in southern Norway, where Breivik is believed to be held, declined to comment or even confirm whether he was currently being held there.
The head of Ila prison outside Oslo, a facility where Breivik was previously held, said in 2013 that holding him in isolation was necessary because of the risk he could take someone hostage.
(Editing by Tom Heneghan)