NEW YORK (Reuters) - The former top administrator of Allentown, Pennsylvania, pleaded guilty on Wednesday to federal fraud charges, becoming the seventh person convicted in a long-running FBI pay-to-play investigation that includes Mayor Ed Pawlowski.

Francis Dougherty, the eastern Pennsylvania city’s former managing director, appeared in U.S. District Court in Allentown and pleaded guilty to conspiracy to commit fraud, according to court filings.

As part of his plea deal, Dougherty admitted to conspiring with Pawlowski, a Democrat, to steer a $3 million street lighting contract to a company whose executives had contributed thousands of dollars to the mayor’s political action committee.

Pawlowski, who has not been charged, is not named in court papers, but he matches the description of “Public Official #3” with whom Dougherty allegedly conspired.

In court documents, U.S. prosecutors have described that person as an elected official in Allentown with authority over city contracts and senior officials like Dougherty.

The unidentified official also announced runs for statewide office and federal office on Sept. 8, 2013, and April 17, 2015, respectively, according to court papers. Pawlowski’s campaign announcements for governor and U.S. Senate were made on those dates.

The six other people who previously pleaded guilty, including several city officials, also implicated Pawlowski. According to court records, the defendants described Pawlowski’s efforts to direct city contracts to companies that had given him campaign funds.

The mayor’s lawyer did not immediately respond to a request for comment on Thursday.

In January, Pawlowski announced his bid for a fourth consecutive four-year term despite the continuing investigation. He has denied any wrongdoing.

Dougherty resigned as managing director, an unelected position, during the investigation.

Allentown is Pennsylvania’s third-most populous city with approximately 120,000 residents.