New Jersey Gov. Chris Christie pushed back Monday night against allegations by a former Port Authority official that Christie knew about lane closures to the George Washington Bridge as they were carried out.

David Wildstein, a Christie associate formerly with the Port Authority, charged last week via his lawyer that "evidence exists" to prove Christie knew about the closures, which were executed in September, apparently for political revenge, and resulted in traffic gridlock in Fort Lee, N.J.

Although a deputy chief of staff to Christie, Bridget Anne Kelly, was shown in subpoenaed emails to have ordered the closures, Christie and his office have insisted repeatedly that the governor only learned of the incident after it happened.

When asked Monday on the "Ask The Governor" radio show whether he had known about the lane closures in advance or as they were carried out, Christie responded, "The answer is unequivocally no."

"I had nothing to do with this," Christie said later in the program. "No knowledge. No authorization. Nothing."

But Christie has inconsistently described when he did first learn about the lane closures. On the radio, Monday, he said "the first time this really came into my consciousness as an issue was when Pat Foye, the Executive Director of the Port Authority’s email about this incident was leaked to the media and reported on."

That report appeared in the Wall Street Journalon Oct. 1. In a previous interview with the radio station, however, Christie said he first read press accounts in September of the lane closures.

Christie suggested Monday that he overlooked those initial press accounts. "When this first became clear to me that this was a potential issue was when the Foye email was put out," Christie said. "[T]here were press accounts before. Whether I read any of those, if I did or heard anything from anybody about traffic, it would not have been meaningful to me."

The questions of when Christie knew about the lane closures and to what extent will not abate any time soon. The New Jersey legislature and the U.S. Attorney are conducting concurrent investigations into the incident and have issued multiple subpoenas.

Christie confirmed Monday that his office was among those subpoenaed by the U.S. Attorney.

“They did that, and I understand why they did it,” he said. “We had already communicated to them that we'd cooperate voluntarily. They decided to send a subpoena, and that's fine. We are complying with that in the same way we are complying with legislative subpoenas."

This story was first published on Feb. 3 at 9:26 p.m.