Norwegian mass-killer Anders Behring Breivik has made a Nazi salute, as he appeared in court for a challenge to the conditions of his detention in prison.

He has arrived for the first day of the hearing, where he is arguing that he is the victim of inhumane treatment.

The 37-year-old right-wing extremist killed 77 people in 2011, when he set off a bomb in Oslo's government district and then gunned down people at an annual summer camp of the Labour Party's youth organisation in July 2011.

He was jailed for 21 years, a sentence that can be extended for the rest of his life.

He claims he has been subjected to "degrading" treatment, with frequent strip searches and handcuffing.

He also says that it is "inhuman" to keep him isolated from other prisoners and to control his mail and visitors.

Norwegian authorities say, in prison, he has a three-room cell with a television and a computer but no internet access.

The Norwegian government says Breivik is being treated humanely and with dignity and that the restrictions placed upon him - including having no contact with other prisoners - are for his own safety, the safety of prison staff and society. 

The government says his mail is controlled to stop him having contact with other right-wing extremists.

Breivik has three cells: one for sleep, one for study and one for exercise. He also has a television, PlayStation and computer without internet.

He can use the exercise yard daily and has recently been allowed to cook his own food.

The four-day hearing is taking place in the prison's gymnasium and Breivik is expected to testify on Wednesday.