ST. PAUL, Minn. (AP) — A Minnesota woman who spent four years in jail after she was accused of participating in a sex trafficking ring has filed a lawsuit against the city of St. Paul and a key police investigator.

In her federal lawsuit, 26-year-old Hamdi Ali Osman alleges St. Paul Police Sgt. Heather Weyker framed Osman as the "madam" in the sex ring of mostly Somali-American immigrants and refugees.

In March, federal prosecutors asked a judge to dismiss all the remaining charges in the sex trafficking case. The request came after a panel of the 6th U.S. Circuit Court of Appeals said Weyker was repeatedly caught lying, and that the sex trafficking claims by two of the alleged victims were likely fictitious.