In initial reports the film's creator was named as Sam Bacile, a supposed US-Israeli real estate developer living in Los Angeles, who purportedly raised $5 million to make the Islamophobic video titled Innocence of Muslims.

The film apparently portrayed the prophet Mohammed as a womanizer and paedophile, sparking anger throughout the Arab world and a riot in which the US ambassador to Libya was killed.

But a day of research by US media and bloggers indicated the film may be a hoax linked to Coptic Christians and Evangelicals living in the United States, who made the low-budget film using actors in Hollywood and then apparently dubbed many of the movie's most provocative statements on to the soundtrack.

A statement from a group claiming to represent the cast said they had been tricked into making the film and that all of the specific attacks on Islam were added by producers in the studio.

They claimed to have been recruited for a film named Desert Warrior.

"The entire cast and crew are extremely upset and feel taken advantage of by the producer. We are 100% not behind this film and were grossly misled about its intent and purpose," the Los Angeles Times quoted them as saying.

"We are shocked by the drastic rewrites of the script and lies that were told to all involved. We are deeply saddened by the tragedies that have occurred."

Suspicions were reaffirmed by The Atlantic.com which quoted a militant Christian activist, Steve Klein, who supposedly worked as a consultant on the film, as saying that Bacile was not Israeli or Jewish and that his name was a pseudonym.

Klein said there were about 15 people involved in making the film. "Nobody is anything but an active American citizen. They're from Syria, Turkey, Pakistan, they're some that are from Egypt. Some are Copts but the vast majority are Evangelical," he said.

One of those supporting the film was Pastor Terry Jones, the controversial Christian fundamentalist preacher from Florida who is notorious for planning public Koran burnings that sparked anti-American riots throughout the Arab world.

Jones is said to have held a public screening of the controversial video at his church in Gainesville, Florida on Tuesday night. "It is an American production, not designed to attack Muslims but to show the destructive ideology of Islam," he said in a statement. "The movie further reveals in a satirical fashion the life of Muhammad."

The key catalyst in bringing the provocation to widespread attention in Egypt appears to have been an Egyptian-American Copt named Morris Sadek from Los Angeles, according to the New York Times.

The paper reported that he highlighted the trailer in an Arabic-language blog post last week. It is unclear whether it was Sadek who dubbed the English-language trailer into Arabic, or whether he was responsible for distributing it to the Egyptian media, whose reports on the video sparked the riots.