Nakoula Basseley Nakoula, 55, was interviewed by federal probation officers at a Los Angeles sheriff's station but was not arrested or detained, authorities said early Saturday.
Federal officials are investigating whether Nakoula, who has been convicted of financial crimes, has violated the terms of his five-year probation. If so, a judge could send him back to prison.
Nakoula went voluntarily to the station early Saturday morning, wearing a coat, hat, scarf and glasses that concealed his appearance. It is unclear whether he returned to his home, which has been besieged by media for several days.
The probation department is reviewing the case of Nakoula, who pleaded no contest to bank fraud charges in 2010 and was banned from using computers or the Internet or using false identities as part of his sentence.
Federal authorities have identified Nakoula, a self-described Coptic Christian, as the key figure behind "Innocence of Muslims," a film denigrating Islam and the Prophet Muhammad that ignited mob violence against U.S. embassies across the Middle East.
Much of the film was shot inside the offices of Media for Christ, a nonprofit based in the Los Angeles-area city of Duarte. The charity raised more than $1 million last year "to glow Jesus' light" to the world.
The Riverside County man who was a script advisor to the film and who has a long history of anti-Islamic activism told the Press-Enterprise newspaper that he has received multiple death threats.
"I'm really tired," Steven Klein said when he answered the door of his home in Hemet, Calif., Friday with a pistol in his hand and clad only in a pair of white shorts stained with what appeared to be ink spots.
The newspaper said Klein, a Vietnam veteran, appeared agitated. While waving the gun, he told the newspaper he was standing up for his First Amendment rights in helping with the film and said he is prepared to die for those rights.
A federal law enforcement official said authorities had connected Nakoula to a man using the pseudonym of Sam Bacile who claimed earlier to be writer and director of the film.
Violent protests set off by the film in Libya played a role in mob attacks in Benghazi that killed U.S. Ambassador Chris Stevens and three other American officials. Demonstrations against American missions have since spread to several other countries.
In his weekly address President Obama denounced the attacks on Americans overseas and defended the filmmaker's religious freedom despite the worldwide violence it has triggered.
"I've made it clear that the United States has profound respect for people of all faiths. We stand for religious freedom. And we reject the denigration of any religion -- including islam. Yet there is never any justification for violence. There is no religion that condones the targeting of innocent men and women. There is no excuse for attacks on our Embassies and Consulates. And so, as long as I am commander-in-Chief the United States will never tolerate efforts to harm our fellow Americans," President Obama said.
KGO contributed to this story.