The Delaware River Port Authority has completed an internal investigation that has raised questions about the way Public Safety Director Vincent Borelli has run his department, according to several sources familiar with the probe.

The investigation was conducted by a former federal prosecutor now in private practice who was hired by the DRPA.

The probe, according to sources, focused on at least two areas: Borelli's use of law enforcement computer-record checks and the conduct of a DRPA police officer following a traffic stop on the Ben Franklin Bridge.

Borelli, who has been informed of the investigation, was not in his office yesterday and could not be reached for comment. His lawyer, Jeffrey Miller of Philadelphia, did not return a phone call seeking comment.

John Matheussen, the chief executive officer of the DRPA, said the issue was a personnel matter and that he could not comment.

Borelli, a former Philadelphia police officer, has been the top policeman at the DRPA for more than a decade, supervising a department that includes about 160 employees. The DRPA owns and operates the Benjamin Franklin, Walt Whitman, Commodore Barry and Betsy Ross bridges, PATCO, the Philadelphia Cruise Terminal and the RiverLink Ferry.

Contact staff writer George Anastasia at 856-779-3846 or ganastasia@phillynews.com.