The Bucks County Courier Times (http://bit.ly/Jo979Z) said 31-year-old Brendan Triplett of Souderton was arrested Friday on charges of institutional sexual assault, a felony, and two counts of intimidation of a witness or victim.
Police say prison officials notified authorities last month that a female inmate complained that Triplett had sexual contact with her at the jail in Doylestown and told the woman not to tell anyone.
Investigators said another female inmate told them she witnessed the alleged assault.
Triplett is being held on $750,000 bail. His attorney, Nino Tinari, did not immediately return a phone call seeking comment.
A corrections department official declined to comment.