David Samson, the former chairman of the Port Authority of New York and New Jersey, is asking a federal judge to block an investigation by the New Jersey State Ethics Commission into allegations that he used his position to benefit clients of his law firm, Wolff & Samson.

The lawsuit, assigned Dec. 8 to U.S. District Judge Michael Shipp of the District of New Jersey, claims the commission has no authority to investigate or bring any action against a Port Authority commissioner since the Port Authority is a bistate agency that is governed by its own conflict-of-interest and ethics rules.