The European Court of Human Rights on Thursday dismissed a complaint by Norwegian mass murderer Anders Behring Breivik over his prison conditions.
Breivik is serving a 21-year sentence for the July 2011 massacre of 77 people, most of them teenagers gunned down while attending a Labour Party youth camp on the small island of Utoeya.
The far-right, anti-Islam extremist took his case to the ECHR after Norway's Supreme Court refused to hear his appeal last year against a ruling that his near-isolation in a three-room cell respected his human rights.
His lawyer argued that the prison conditions breached articles 3 and 8 of the European Convention on Human Rights: the former prohibits inhuman or degrading treatment, the latter guarantees a right to privacy and family life.
"His state (of mind) is deteriorating", his lawyer Oystein Storrvik told AFP. "He is no longer able to study for example."
But the court based in Strasbourg said that "its examination of the case did not reveal any violations of the Convention, and rejected the application as inadmissible for being manifestly ill-founded."
Norwegian officials have repeatedly rejected allegations that Breivik is isolated, arguing that he is treated as a "VIP prisoner" and has regular contact with prison staff, his lawyer and visitors.
He has the use of three cells, each measuring more than 10 square metres and equipped with a television, computer, DVD player and gym gear. He has no internet connection, however.
Survivors of the Utoeya massacre expressed satisfaction at the ruling.
"It's a relief. We're hoping not to hear his name again for many years to come," Lisbeth Kristine Royneland, the head of a victims' support group whose 18-year-old daughter was killed by Breivik, told AFP.
Writing on Twitter, a survivor of the massacre, Tore Remi Christensen, wrote: "The Breivik case is rejected in Strasbourg. Delighted. May he and all those who share his shitty message rot in hell."
Breivik's killing spree began on July 22, 2011, when he set off a bomb outside a government building in Oslo, killing eight people.
Disguised as a police officer and armed with a semi-automatic rifle and pistol, he then went to Utoya where the Labour Party was holding a youth camp, killing 69.
During his trial the extremist, who has changed his name to Fjotolf Hansen, repeatedly addressed the courts with Nazi salutes and complained about the cold coffee and frozen meals served in prison, among other things.
His sentence can be extended indefinitely if judges determine he remains a threat to society.