(CNN) - The Democratic co-chairman of a legislative committee investigating the George Washington Bridge scandal has reviewed subpoenaed documents, and has concerns about the role of a top appointee of New Jersey Gov. Chris Christie at the agency overseeing the bridge.
Assemblyman John Wisniewski told CNN that David Samson, the chairman of the Port Authority of New York and New Jersey, is "deeply involved" in its operations.
"The concern that I have, that in a sense is ratified by the reading of the documents, is what is supposed to be an independent agency has clearly become the subdivision of the governor's office," Wisniewski said.
"When you have an agency like this, that has very little accountability, it allows things like the lane closures to happen."
Wisniewski's committee is investigating if senior officials from the Port Authority and Christie's office ordered access lanes to the bridge in Fort Lee closed last September as an act of political retribution against the town's mayor for not endorsing Christie for reelection.
The scandal has called into question Christie's governing style and clouded any prospects of a 2016 presidential bid. The committee has issued multiple subpoenas to top Christie advisers.
The U.S. Attorney's Office is also investigating.
Christie has denied knowing anything about the lane closures until after they occurred and then only from media reports. He also denies knowledge of any political mischief by his appointees.
But Wisniewski said the subpoenaed documents, which have not been made public, show Samson involving the governor's office in a level of Port Authority "minutiae" that raises questions about Christie's denials.
"There's something about this story that doesn't add up," he said.
Wisniewski also has questions about Samson's dual roles as Port Authority chairman and founding member of a powerful New Jersey law firm.
Wisniewski noted that Samson’s law firm represented New Jersey Transit’ when Samson voted to reduce the transit agency's rent on a parking lot from more than $900,000 per year to $1 per year.
And Samson’s firm represented The Rockefeller Group’s development in Hoboken when the Port Authority approved a $75,000 study of the development site.
"Part of being in the weeds," Wisniewski said, "is deciding who gets these contracts."
The governor's office declined to comment.
A spokesman for the Port Authority referred questions to Samson's personal spokeswoman, who sent CNN a statement from his lawyer.
"I trust that the chairman will lead an impartial investigation as he pledged," said Michael Chertoff, a former appeals court judge and U.S. homeland security secretary.