The players at the center of the George Washington Bridge lane-closing scandal are not finished causing headaches for Gov. Chris Christie.

The latest indication comes in a sworn statement by David Wildstein, a former Port Authority official and the admitted mastermind of the access-lane closings, that describes Mr. Christie breaking the law as he exercised a heavy hand over state politics from the front office.

Mr. Wildstein’s statement, in a civil case separate from the federal prosecution in the bridge case, offers the first insider confirmation of a long-rumored tale of New Jersey political corruption, and places Mr. Christie at the center of it. It also portrays the governor, a former United States attorney, casually revealing information about a grand jury proceeding he had overseen, which violates federal law.

It reinforces nagging doubts about Mr. Christie just as he says he is preparing to make an announcement this month about whether he will seek the Republican nomination for president. Even apart from the potential violation of grand jury laws, the statement reinforces the image of Mr. Christie as an intensely hands-on manager who used the Port Authority of New York and New Jersey, which runs the George Washington Bridge, to deal with political problems. And Mr. Wildstein, a former political blogger who is known as a pack rat with a long memory, indicated that this may not be the end: His statement says he has emails and further “documents to be produced for inspection.”