The inspector general, Anthony L. Maniscola, said that although his inquiry was in its earliest stages, he already had determined that the allegations, even if proven true, would not present a danger to motorists.

The allegations were made by a former construction inspector, Bob Dietz of Lancaster, who worked for a subcontractor during the four-year project.

The highway was reconstructed and expanded from four to six lanes for a 7-mile stretch between Valley Forge and Norristown. The project was finished late last year.

In an interview yesterday, Dietz said he raised concerns during construction that a retaining wall along a section of the road was leaning six inches in the wrong direction and that the contractor had used less than a third of the concrete required on two bridge decks. He said the alleged shortcuts were likely to trigger expensive repairs in the years to come.

"I brought it up during project meetings, but there was a lot of pressure to just get the project done," Dietz said. "Nobody wanted to hold up the contract. You would think they would want a first-class job."

Mark Compton, director of government affairs for the contractor, Alan A. Myers Inc. of Worcester, Montgomery County, called his company's performance on the job outstanding and said the allegations came as a surprise.

"This is the first we're hearing of this," Compton said. "No authorities have contacted us. If and when we are contacted, we will cooperate to the full extent possible. . . . We had no quality complaints. So I'm not sure what this is about."

Maniscola confirmed that he was reviewing "allegations of irregularities" related to the Valley Forge work, but declined to discuss the specific claims Dietz has made.

"We are still making a preliminary assessment," said Maniscola, who was named the turnpike's first inspector general in February. "Allegations come in, we have to investigate them. We're not saying anyone's guilty of anything. We're just looking into it."

Maniscola, a former special agent for the Pennsylvania Attorney General's Office, said he had asked the FBI to assist him because it had forensic-accounting resources needed to perform the review. FBI spokesman J.J. Klaver said yesterday that the bureau does not confirm or deny its involvement in investigations.

Dietz said an FBI agent was present when Maniscola interviewed him twice this month. Dietz said that he told the investigators about alleged construction shortcuts and that he had made no accusations of criminal wrongdoing.

Maniscola called "totally bogus" blog reports this week that the FBI had conducted a search-warrant raid at turnpike headquarters, and that the federal government had subpoenaed documents or computer equipment related to the Valley Forge project.

The inspector general also said the Valley Forge review was unrelated to a statewide grand jury's pay-to-play probe of the Turnpike Commission and the federal corruption investigation of former State Sen. Vincent J. Fumo.

Fumo is serving a 55-month sentence for misappropriating millions from the state Senate and a South Philadelphia charity. The charity's executive director, Ruth Arnao, a former Fumo Senate aide, was sentenced to a year and a day in prison. Her husband, Mitchell Rubin, was removed from the Turnpike Commission by Gov. Rendell in March after it was disclosed that he had been formally notified that he was a target of a Fumo-related FBI investigation.

In their case against Fumo, prosecutors successfully argued that he paid Rubin $150,000 in taxpayer money from 1990 to 2004 for contracted consulting work, though Rubin never performed any state duties.