US authorities have arrested the wife of the gunman who killed 49 people at an Orlando gay nightclub last year.

The wife of Omar Mateen, who was killed by police during the rampage at the Florida club in June, was arrested at her home outside San Francisco, the New York Times reported, citing an unnamed law enforcement official.

Noor Salman faces federal charges of obstruction of justice, and aiding and abetting the attempted provision of material support to a foreign terrorist organization, ABC News reported, citing the FBI and her lawyer.

Salman, who was repeatedly questioned by law enforcement interrogators after the club attack, is expected to appear in court on Tuesday. She will then face extradition to Tampa, where she was indicted, ABC reported.

Salman moved to the San Francisco area after her husband was killed in a shootout with SWAT team members during the June 12 massacre at the Pulse nightclub in Orlando.

Mateen pledged allegiance to the Islamic State group in a 911 call to emergency officials during the standoff. He also made a series of Facebook posts and searches before and during the attack.

Last month, Salman filed a petition in a California court to change the name of the son she had with Mateen.

– with ABC