ST. LOUIS -- A St. Louis man is accused of forcing a 16-year-old girl into prostitution.

Federal authorities on Tuesday announced the arrest of 27-year-old Reginald Williams. He is charged with interstate transportation of a minor with the intent to engage in prostitution for allegedly transporting the girl throughout the St. Louis area, and to the Chicago area.

Police in Collinsville, Ill., learned this month that photos of a missing 16-year-old were included on a website implying she was available for sex. The website said the girl was 20 but police confirmed she was 16.

Authorities learned another girl was believed to be with the 16-year-old at a St. Louis County hotel. Federal prosecutors say Williams was arrested at the hotel, where police found both girls.