LOS ANGELES, USA (AP) - A Southern California filmmaker linked to an anti-Islamic movie inflaming protests across the Middle East was interviewed by federal probation officers at a Los Angeles sheriff's station but was not arrested or detained, authorities said early today.

Nakoula Basseley Nakoula, 55, was interviewed at the station in his hometown of Cerritos, California, Los Angeles County Sheriff's Deputy Don Walker said.

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 US 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.