A Tier II sex offender, identified as Matthew Campbell, 30, was arrested by Dover Police after it was discovered he allegedly had sexual relations with a 17-year-old girl.
The alleged rapes were reported July 24, said police spokesman Cpl. Mark Campbell.
Campbell was convicted in April 2012 for unlawful sexual contact with a person under the age of 18, according to the Delaware Sex Offender Registry.
Already jailed at the James T. Vaughn Correctional Center, Smyrna, Campbell was charged with five counts of fourth-degree rape, for which he was ordered held in default of a $100,000 secured bond.