PHILADELPHIA — The former head of the Pennsylvania Turnpike Commission was charged Wednesday with obstruction of justice in the investigation of a former state senator who gave him an alleged no-work contract.

Mitchell Rubin, 58, of Philadelphia, was charged in connection with the grand jury investigation of former state Sen. Vincent Fumo, who was convicted on fraud and related charges a year ago.

Rubin withheld information about the circumstances that led to his company, B&R Professional Services, getting a Senate contract and the reasons for it, according to court papers filed by the U.S. attorney's office in Philadelphia. He also withheld information about his relationship with Fumo, prosecutors said.

Prosecutors interviewed him in March 2006 while trying to determine if the contract was legitimate or if it was an improper use of public funds.

"The victim, in a sense, is the criminal justice system and the efforts to get the facts," Assistant U.S. Attorney John Pease said. "Rubin thwarted the efforts of the grand jury."

Wednesday's court filing, known as a criminal information, is typically part of a plea deal. Pease would not say if an agreement had been reached.

Rubin's attorney, Barry Gross, declined to comment on the accusations and would not say if his client was cooperating with authorities.

Fumo, a longtime Democratic powerbroker, and his aide Ruth Arnao, who is Rubin's wife, were convicted after a federal trial last March. Fumo was sentenced to 55 months in prison for fraud, obstruction and tax evasion; Arnao was sentenced to a one-year prison term. Two fraud counts against Fumo were based on the Senate contract Rubin held to serve as legislative consultant to the Senate Democratic Appropriations Committee, which Fumo chaired.

B&R Professional Services provided court reporting, document retrieval and other services to attorneys. Its contract with the Appropriations Committee provided $30,000 a year for five years, ending in 2004.

The contract indicated that Rubin would do "research, analysis and make recommendations on legislative matters, assist on constituent services," according to court papers. But at Fumo's trial, federal prosecutors said Rubin's contract was fraudulent.

Rubin and Arnao got married in 2005 and participated in Fumo's lavish lifestyle, vacationing with him on a yacht illegally commandeered from a maritime museum and enjoying catered French meals while on board. Just over a week after the conviction, Gov. Ed Rendell removed Rubin from the Turnpike Commission, citing the federal probe.

In a letter announcing his decision, Rendell cited "overwhelming" evidence that Rubin accepted $150,000 in taxpayer-paid work that apparently was never done.