A Pennsylvania Department of Transportation consultant has been charged with perjury for allegedly lying to a grand jury impaneled to investigate potential corruption within the agency's Southeastern Pennsylvania district.

Joseph DeSimone, 33, of the 2400 block of Hicks Street in South Philadelphia, was arrested Thursday morning.

DeSimone acted as a PennDOT consultant inspector through his job at Construction Methods and Coordination, according to the office of the state Attorney General.

DeSimone was called to testify before a grand jury on Dec. 17, 2013, about eight months into a state probe of the PennDOT district covering Philadelphia, Delaware, Chester, Montgomery and Bucks counties.

Prosecutors said a confidential source claimed consultant inspectors working in that district were systematically overbilling PennDOT for time purportedly spent performing inspections under the agency's Highway Occupancy Program.

Prosecutors also said evidence indicates many inspectors were illegally paying PennDOT district supervisors who permitted the overbilling to occur.

Before appearing in front of the grand jury, DeSimone allegedly called the confidential source and attempted to find out what the source had told investigators. DeSimone is accused of failing to disclose those conversations to the grand jury when asked.

DeSimone was arraigned Thursday and his bail was set at $25,000. He's next due in court May 2 for a preliminary hearing.

If convicted, DeSimone faces a maximum possible penalty of seven years in prison and a $15,000 fine.