NEW YORK (CBSNewYork)Manhattan District Attorney Cyrus Vance is the latest investigator digging into the relationship between New Jersey Gov. Chris Christie‘s administration and the Port Authority.

According to published reports, Vance’s office issued a subpoena for documents related to several projects, including the rebuilding of the World Trade Center and nearly $2 billion in road construction contracts. The Pulaski Skyway, which was partially closed Saturday as part of a two-year rehabilitation, is among the projects reportedly being scrutinized.

The DA’s office is particularly interested in the voting records of Christie-appointed Port Authority commissioners and potential conflicts of interest, sources say.

Both the governor’s office and the Port Authority declined to comment.

WEB EXTRA: Guide To Navigating Northbound Pulaski Skyway Shutdown

The U.S. attorney and New Jersey state lawmakers are conducting their own investigations into the Christie administration over September’s lane closures at the George Washington Bridge in Fort Lee, which appear to be political retribution for the town’s mayor not supporting Christie’s re-election bid last year.

Meanwhile, in a report in the Newark Star-Ledger, three former members of the State Ethics Commission accuse the governor’s office of interfering with the agency. According to the report, in 2010, the commission was investigating Barbara Panebianco, a member of Christie’s staff, who used her state email account to influence her county health department to handle feral cats on her property in Bordentown.

As ethics officials were looking into the matter, a possible conflict-of-interest violation, the director of the agency was fired and replaced with one of Christie’s one lawyers, the newspaper reported.

Republican state Sen. Bill Schluter, the commission’s former vice chairman, said it was the first time a governor had asked the commission’s top investigator to be removed.

“These moves strike at the heart of the State Ethics Commission in the public’s eye, undermining its independence and integrity” Schluter told The Star-Ledger.

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