Killer Anders Breivik's human rights were not violated by isolating him in prison and his appeal has been rejected, says a court.

He claimed being in solitary confinement in "inhumane" conditions had damaged him and made him even more radical in his neo-Nazi beliefs.

But Norway's top court upheld a ruling made by the court of appeal in January, saying there was "no basis" for a different conclusion.

Following the latest judgment, the murderer's lawyer, Oystein Storrvik, said he will take the case to the European Court of Human Rights in Strasbourg.

Mr Storrvik said: "We've always been prepared for the possibility that our case before the Norwegian courts may not succeed."

Last year, the country's government had appealed a lower court ruling that Breivik's isolation behind bars violated his rights.

He is currently serving a 21-year jail term for killing 77 people in a bomb and gun attack in 2011.