"A man in his 20s is officially suspected of attempted murder after the shooting at Mullah Krekar's apartment," Norwegian police said in a statement, adding that they had requested the man's extradition from Sweden.
Swedish authorities confirmed they had received an extradition request for 20-year-old Mohammed Ehsan Baba, who lives in Gothenburg.
He was arrested in the southwestern Swedish city on Wednesday and remanded in custody Friday, the prosecutor on the case, Thomas Ahlstrand, told AFP. His extradition should take "several weeks," he said.
Norwegian commercial broadcaster TV2 had reported about the arrest earlier, quoting Baba's lawyer, who said his client, reportedly neither a Swedish nor a Norwegian citizen, denied the allegations against him.
The shots were fired at Mullah Krekar's fourth-floor apartment on the night of January 24th, 2010. Krekar, 54, who has lived in Norway for 20 years, was not injured in the attack, but his British brother-in-law was shot in the hand.
Krekar, whose real name is Fateh Najmeddin Faraj, admitted that he co-founded Ansar al-Islam in 2001, but insists he has not headed it since May 2002. He and the group figure on United Nations and US lists of terrorist groups or individuals.
Krekar has been living under risk of deportation since 2003 after Norwegian authorities ordered him expelled, claiming he posed a threat to national security.
While Norway's court system has upheld the ruling, Norwegian law prevents him from being deported to Iraq, where he risks the death penalty.
Krekar has often supported the insurgency in Iraq, comparing the US occupation of the country to the Nazi occupation, and has also described Al-Qaeda chief Osama bin Laden as a "good Muslim."