The right-wing extremist who confessed to killing 77 people in a bomb and shooting rampage in Norway is not criminally insane, a psychiatric assessment found on Tuesday, contradicting an earlier examination.

Norwegian right-wing extremist Anders Behring Breivik, 32, arrives in court in Oslo on Feb 6. Daniel Sannum Lauten / Agence France-Presse?

The new conclusion comes just six days before Anders Behring Breivik is scheduled to go on trial on terror charges for the massacre on July 22, and could prompt prosecutors to seek a prison sentence instead of compulsory commitment to psychiatric care.

It conflicts with an earlier assessment, which found Breivik psychotic both during and after the attacks, and diagnosed him as a paranoid schizophrenic.

The court will take both psychiatric assessments into account during the trial, which starts on Monday and is scheduled to last 10 weeks.

The new assessment was made by psychiatrists Terje Toerrissen and Agnar Aspaas on a request from the court after widespread criticism against the first diagnosis.

"Our conclusion is that he is not psychotic at the time of the actions of terrorism and he is not psychotic now," Toerrissen said.

The full report was confidential and the psychiatrists declined to give details on why they reached a different conclusion than the first team of experts that examined Breivik. They said they will present their reasoning when they testify in the trial.

Their lengthy report is based on 11 interviews with the accused, three weeks of permanent observation and the police interrogation transcripts.

AP-AFP