The alleged scheme was all about relationships.

The head of a Montgomery County engineering firm wanted to win Pennsylvania Department of Transportation contracts to inspect road-maintenance and bridge-cleaning projects, investigators said. So he befriended a retired PennDot employee who had mentored the man in charge of picking the recipients of the agency's six-figure deals.

For the businessman, Christopher Czop, the relationship was lucrative, investigators said, with his firm securing more than $800,000 in contracts and him paying himself at least $200,000 annually.

In turn, Czop Specter Inc., of Norristown, allegedly hired the PennDot official's friends and family.

The state Attorney General's Office on Thursday charged Czop with corruption and related counts, part of an ongoing probe of alleged graft within the PennDot district that serves the five-county region.

Twelve people were charged last year, and more might follow Czop, 45, of Collegeville.

"We're in the process of trying to uncover and obtain evidence of any and all criminal activity that was occurring there," said Chief Deputy Attorney General Erik Olsen, who has overseen the investigation.

After his arrest, Czop was arraigned in Montgomery County Court and released on $100,000 bail. His attorney, Ethan O'Shea, called the allegations false and based only on supposition and innuendo.

"Mr. Czop is proud of his reputation for uncompromising integrity and excellence, and intends to vigorously defend himself in this matter," O'Shea said in a statement.

Although he was unnamed in court records, the PennDot executive involved in the alleged scheme was Nicholas Martino, who until last year served as District 6's assistant district executive for maintenance. He has not been charged, although he has been subpoenaed to testify in the ongoing probe.

"I have no hesitation in saying that Mr. Martino has maintained his innocence from day one," his attorney, Anthony Voci Jr., said. "I have not seen one shred of evidence that would cause me to doubt that."

Voci added that Martino lacked the authority to award contracts, saying that responsibility was vested in Harrisburg higher-ups.

The retired PennDot employee who allegedly served as a go-between for Czop and Martino, making more than $100,000 for his efforts, was not named in the court documents, but his company - FJG Consulting - was. The president of that firm is listed in public documents as Frank Graff, whom sources confirmed as the alleged liaison. Graff, who retired as a county manager, could not be reached for comment.

Richard Kirkpatrick, a PennDot spokesman, said the agency has taken several steps to eliminate any possible wrongdoing at District 6. For example, it suspended relationships with the various contractors that have been implicated, beefed up in-house staff as well as oversight, and called for an outside review of its practices.

"In her press release, Attorney General Kathleen Kane thanked PennDot for its cooperation," he said. "As soon as we were tipped, we immediately investigated and took corrective steps."