(CNN) -- A Michigan man and woman convicted of trying to extort $680,000 from "Glee" actor John Stamos by threatening to sell compromising photos were each sentenced to four years in prison Friday.
U.S. District Judge R. Allan Edgar in Marquette said the photos never existed, according to a federal prosecutor.
Scott Edward Sippola, 31, and Allison Lenore Coss, 24, could have faced up to nine years in prison for convictions of conspiracy and interstate communications to extort money.
Assistant U.S. Attorney Paul Lochner said a statement from Stamos was read in court. In it, Stamos said he had been slandered and his reputation impugned. Lochner said the judge ascertained that the conspiracy wasn't just a "foolish lark."
In a presentence filing, Sippola admitted his conduct "was awful."
"I sought to exploit my knowledge of the personal weaknesses of a perfect stranger for my own undeserved financial gain," Sippola wrote.
"The case was made by the fact that these defendants made threats to damage his [Stamos'] reputation in order to have him pay them," Assistant U.S. Attorney Maarten Vermaat said after the July verdict in Marquette, Michigan.
According to CNN affiliate WLUC, prosecutors said that Coss and Sippola told Stamos that if he didn't give them the money, they would sell embarrassing pictures of him allegedly using drugs to tabloid publications.
Vermaat said the defendants sent about 40 e-mails to Stamos threatening to sell the photos. FBI agents got involved and started monitoring Stamos' e-mail account and "eventually communicated by cellular telephone with the defendants pretending to be Mr. Stamos' business manager." Sippola and Coss were arrested in December 2009 at an airport, a pre-arranged dropoff spot for the money.
Defense attorney Sarah Henderson alleged at trial that Stamos had a fling with Coss when she was a 17-year-old vacationing on spring break in 2004. Prosecutors said Stamos met Coss during a trip to Disney World in Orlando, Florida. They developed a friendship and the two communicated by e-mail occasionally until November 2009, when the actor turned the photos matter over to the FBI.
According to WLUC, Coss testified there were several photos depicting Stamos using cocaine. She claimed the actor seemed interested in buying the photos.
The television actor, who also appeared in "Full House" and "ER," testified that nothing inappropriate happened at a 2004 spring break party and, accordingly, he didn't believe compromising photos existed.
Coss also filed a memorandum before sentencing, asking for a lighter sentence because she is a "good person who acted out of character."
"The defendant was misguided in her thinking that asking for money to prevent selling photographs was a legitimate business transaction," the filing states.
Calls by CNN to defense attorneys Friday were not immediately returned.
CNN's Phil Gast contributed to this report.