Norwegian mass murderer Anders Breivik gave a Nazi salute on his return to court, where his lawyers will argue that his detention in solitary confinement constitutes an infringement of his human rights.

Breivik, 37, who appeared with his head shaved and wearing a dark suit, raised his right arm in salute after his handcuffs were taken off in the courtroom set up in Skien prison, 130 km south-west of Oslo, where he is being held.

Breivik killed eight people in a bomb attack in central Oslo, before shooting 69 people, most of them teenagers, in an attack on a Labor Party youth camp on the island of Utoya. He has been held in solitary confinement in the prison after being handed a 21 year sentence in 2012.

Breivik accuses the Norwegian government of breaching two clauses of the European Convention of Human Rights. One guarantees to right to "private and family life" and correspondence, and one prohibits inhuman of "inhuman or degrading treatment or punishment". His lawyer, Oystein Storrvik, told AFP Breivik had been "very stressed due to his isolation".

"One of his main things to do (in prison) was to study and he has stopped that now, and I feel that is a sign that isolation has been negative to his psychological health," Storrvik said.

Norwegian authorities claim his correspondence is monitored to prevent him communicating with far-right activists and sympathisers, and the conditions of his detention are "well within the limits of what is permitted" under the convention. They say Breivik has access to three cells, as well as a television, games console and computer without internet access, and is able to cook for himself and do his own laundry.

"There are limits to his contacts with the outside world which are of course strict... but he is not totally excluded from all contact with other people," the state's lawyer Marius Emberland told AFP.

The hearing is expected to run until Friday (18 March), with Breivik to testify on Wednesday (16 March).

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