The alleged extortionists were arrested last week in an FBI sting operation after they met with an undercover agent posing as a Stamos representative for a money drop in a Michigan airport, authorities say.
A raid on the home of Allison Coss, 23, and Scott Sippola, 30, of Marquette, Mich., turned up three photos of Stamos, a piece of paper with Stamos's personal cell phone number on it, and a list of three tabloid magazines with contact numbers for each, according to the FBI.
"John Stamos was the target of an extortion attempt," says Matt Polk, a rep for the actor, who is currently starring in Bye Bye Birdie on Broadway. "The U.S. Attorney and the FBI handled the investigation swiftly and with great expertise."
Stamos, 46, described only as "Mr. X" in a Dec. 3 FBI affidavit, was vacationing in Florida in 2004 when he met Coss. At the time, the pair and another friend attended a party where photos were allegedly snapped of the actor.
It remains unclear if the party occurred before or after Stamos and actress Rebecca Romijn announced their split that year.
Following the party, the actor stayed in touch via email with Coss for some time, according to the FBI. Then last month, Stamos began receiving email threats from a person named "Brian L" who allegedly demanded $680,000 from Stamos or else the photos would be sold to a tabloid "thereby causing harm to Mr. X's reputation," says the legal filing, which does not describe the photos in detail. Coss indicated in emails to Stamos that she was aware of the plot.
Upon receiving the threats, Stamos contacted his attorney, who alerted the FBI late last month, the papers say.
"The photos in question are photos of John posing with fans," says Stamos's rep. "At the conclusion of the investigation and hearing, the photos will be available and the public will be able to see that the photos are simply John posing with fans."
Both suspects have since posted bond, and the case is still pending.
The alleged extortion plot was first reported by The Smoking Gun.