Judges at a Norwegian court on Tuesday unanimously rejected mass killer Anders Behring Breivik's application to be released on parole.
The right-wing extremist was convicted of the murder of 77 people in Oslo and on the island of Utoya nearly 10 years ago.
The Telemark district court sitting in Skien, some 130 kilometres south-west of Oslo, had been weighing for the past two weeks whether Breivik continues to pose a threat to society.
During the parole hearing on January 18, Breivik arrived in the courtroom carrying a laptop bag with a right-wing message written on it. He also gave a Nazi salute.
In their brief judgement issued on Tuesday, the court sided with the public prosecutor's office and said Breivik should be kept behind bars.
Breivik, who is 42 and calls himself Fjotolf Hansen, detonated a car bomb in the government quarter in Oslo, killing eight people on July 22, 2011.
He then carried out a massacre of people attending a youth camp organized by Norway's Labour Party, killing 69, most of them young people.
Breivik cited right-wing extremist and anti-Islam motives for his crimes, the worst terrorist attack in the country since World War II.
The Oslo District Court in 2012 sentenced him to 21 years - the maximum possible at the time. He is allowed to seek parole after 10 years, with the court determining whether the early release is warranted.
Breivik's sentence also came with a "preventive detention" clause that allows him to be kept behind bars even after 21 years if he is deemed a continued threat to society - meaning he could die in prison.