OSLO (Reuters) - Norway said on Wednesday it was not violating mass killer Anders Behring Breivik’s human rights by keeping him in isolation, ahead of a lawsuit he is bringing to change the conditions of his detention.

Norwegian mass killer Anders Behring Breivik reacts as he returns after a break to the court room, in Oslo Courthouse August 24, 2012. REUTERS/Stoyan Nenov

Breivik, who killed 77 people in a bomb attack and shooting spree in 2011, argues his effective solitary confinement makes him a victim of cruel and inhuman treatment.

“There is no evidence that the plaintiff has physical or mental problems as a result of prison conditions,” the Office of the Attorney General, the Norwegian state’s legal office in civil lawsuits, wrote in a document sent to the Oslo District Court and released on Wednesday.

The Norwegian Correctional Service denies Breivik is held in solitary confinement, preferring the phrase “excluded from the company of other prisoners”. There is no maximum time for how long he can be held in such “extra high security”, a service official previously told Reuters.

Breivik, who has been held alone since his arrest, argues the regime is degrading and is a breach of the European Convention on Human Rights.

The hearing, scheduled for March 15-18 in the gym of Skien prison where Breivik is held in southern Norway, has prompted renewed soul-searching in a country where many want to move on from the killings.

According to the Attorney General’s document, Breivik has access to three different prison cells - for living, study and exercise - between which he can move freely. He can take walks in a yard and he can cook his own food and do his laundry.

He also has access to a computer without Internet, television and a PlayStation.

Breivik’s lawyer says his client only has had contacts with professionals, such as prison staff, his lawyers and his mother, when she was alive, according to a separate court document published late on Tuesday.

“According to the information available, they (Breivik and his mother) only had five minutes together when they could hug each other,” it said. Breivik’s mother died from cancer in 2013.

The document also said Breivik’s mail was being monitored to a degree where “he doesn’t feel he could form relationships through letters”.

He considers this a breach of “his right to respect for his private life and his correspondence”, also part of the European Convention on Human Rights.

Norway says control over prisoners’ communication is not in itself a violation, because it could uncover information about the planning or commission of criminal offences.

Breivik wrote in his extreme right-wing manifesto discovered after the killings that prisons were considered ideal recruitment places, the Attorney General’s document said.

He is serving a 21-year sentence, the maximum in Norway. The term can be extended if he is still considered a threat.