A Polish company sold chemical fertilizer to Norwegian bomber and gunman Anders Behring Breivik but the transaction was entirely legal and police have made no arrests, the Polish internal security agency said Monday.

Breivik killed more than 90 people in last Friday's bomb attack and shooting rampage that stunned Norway.

"According to our experts, the materials bought in Poland were not critical for the construction of the bomb," the deputy head of the ABW agency, Pawel Bialek, told a news conference.

"At this stage, the information and materials we have do not indicate that the relations with the terrorist were anything other than commercial."

Bialek said the owner of the company, which he did not name, was cooperating fully with the authorities in their investigation. He added that the firm had sold over 100 kg of one substance and several hundred grams of another.

The transaction was made over the Internet and there is no evidence that Breivik ever visited Poland, Bialek said.

Breivik also tried unsuccessfully to buy weapons in the Czech Republic, Bialek added.

In a rambling, 1,500-page online manifesto, Breivik, who has confessed to the killings, portrays himself as a crusader defending Europe against a tide of Islam.

He names the 17th century Polish king Jan III Sobieski, who defeated the Ottoman Turks at the gates of Vienna, as one of his heroes, Polish media have reported.