ATTLEBORO - An assistant Bristol County prosecutor accused of sexually assaulting a 17-year-old girl in an Attleboro District Court conference room was not supposed to be alone with the teen under the district attorney's office policy.

The allegation that Pete Joseph Costanza was alone with the girl in the room adjacent to the district attorney's office is one of the issues that will be reviewed in an internal investigation regarding his continued employment, said Gregg Miliote, a spokesman for Bristol County District Attorney Sam Sutter.

Costanza was suspended without pay as a result of the charges against him, pending an internal review expected to be completed by the end of the week, Miliote said Tuesday.

Since he took office in January 2007, Sutter has had an office policy against one-on-one meetings with victims, witnesses or other people being interviewed, Miliote said.

"That will be part of many things that are going to be looked into" as part of Costanza's review, Miliote said. Sutter recused his office from the criminal prosecution of Costanza, who pleaded innocent Monday to indecent assault and battery, attempted extortion and assault and battery.

He is free on $10,000 cash bail and his case will be prosecuted by the Plymouth County District Attorney's Office. Miliote said it is a conflict for Sutter's office to prosecute one of it's own employees.

Prosecutors say Costanza used his position to try to extract sexual favors from the girl last Friday in the conference office. They confiscated his cell phone and allege he called the girl repeatedly on her cell phone. Investigators have sent what they say was saliva evidence for DNA testing.

The girl was in court because her boyfriend was in custody in drug and domestic assault cases and she thought Costanza could help get him released, prosecutors said.

Daniel O'Malley, Costanza's lawyer, said the veteran prosecutor denied the allegations.

The conference room, where the incident is alleged to have occurred during the court lunch break after 1 p.m., is open to court employees only or lawyers and is also located near an employee bathroom.

The small room has a door, which the girl says Costanza closed, but it has a large smoked-glass window which is translucent.

Attleboro Detective Russell Castro and Joseph Collins, a state police detective assigned to the Bristol County District Attorney's Office, were at the court again on Tuesday to talk to court employees who are witnesses or potential witnesses in the case.