MARQUETTE, Mich. (AP) -- A federal appeals court has upheld the convictions of a man and woman from Michigan's Upper Peninsula who were accused of trying to blackmail actor John Stamos.

A three-judge panel in Cincinnati rejected challenges to the indictment Monday as well as claims that Allison Coss and Scott Sippola should have received a break at sentencing for accepting responsibility.

They were sentenced to four years in prison in 2010 after a jury convicted them of conspiracy and using email to threaten a person's reputation. Coss and Sippola threatened to sell old photos of Stamos with strippers and cocaine to the tabloids unless he paid $680,000. The FBI said the photos didn't exist.

Stamos met Coss in Florida in 2004 and had a friendship.