Norway's mass murderer Anders Behring Breivik has sued the government for violating his human rights by exposing him to extreme isolation in prison, media reported.
"We delivered the legal papers to the Oslo District Court," Xinhua quoted local newspaper VG as saying on Wednesday.
"The main reason for the lawsuit is the extreme isolation my client has been exposed to," Behring Breivik's lawyer Oystein Storrvik was quoted as saying.
Storrvik said that Breivik was being subjected to inhuman treatment at prison.
Breivik has been living under the highest security of any prisoner in Norway without any contact with other inmates and visits have been very limited.
"My client's communication with the outside world has been severely restricted. Mails have been either totally banned or strictly censored," Storrvik said.
The Norwegian government has previously said that Breivik's prison conditions comply with European laws.
Breivik, 33, set off a car bomb that killed eight people outside government headquarters in Oslo on July 22, 2011 and then killed 69 others in a shooting rampage on Utoya Island, where young members of the governing Labor Party had gathered for their annual summer camp.
In 2012, Breivik was sentenced to 21 years in prison at the Oslo District Court.
Norway's penal code does not have the death penalty or life imprisonment, and the maximum prison term for Breivik's charges is 21 years. However, inmates who are considered a threat to society can be held indefinitely.
