A Norwegian author who obtained private emails written by mass murder Anders Behring Breivik has urged police to reopen the investigation.

Kjetil Stormark has just released a new book based on Breivik’s Internet correspondence.

He says they show investigators have not done enough to probe the the theory that the 33-year-old has a vast international network.

“That the police during the trial said that it is impossible to find anyone else from the Knights Templar network – which Brievik claimed exists – among the 8,000 people he tried to send his manifesto to is completely unacceptable,” Stormark said.

The journalist obtained the killer’s emails from a hacking group last year. He handed them to police before starting his work.

The book also details how Breivik raised funds and acquired all the equipment for his killing spree in Oslo and Utoya in July last year.