Norwegian police are to question 32-year-old Anders Behring Breivik again about the bombing and shooting massacre that killed at least 76 people.
Police lawyer Paal-Fredrik Hjort Kraby told a news conference they will interview him again today.
Breivik has confessed to the attacks, saying he was trying to save the Western world from Muslim colonisation and justifying the rampage in a 1,500-page anti-immigrant manifesto.
His lawyer has said he considers himself a "saviour" and that it is likely he is insane. He has pleaded not guilty to the terrorism charges he faces.
Breivik claimed wide contact with individuals and groups he says support his opposition to immigration. But questions persist about whether there was a genuine network or if Breivik's statements were exaggerations.
Prime Minister Jens Stoltenberg said an independent commission will be formed to investigate the attacks and the level of response.