The former Port Authority of New York and New Jersey executive who orchestrated the George Washington Bridge lane closures is cooperating with federal prosecutors investigating the scandal, Esquire reported on Monday.

According to Esquire’s Scott Raab, sources close to the investigation say that David Wildstein has been cooperating with Paul Fishman, the U.S. attorney in New Jersey. Raab also reported that Fishman has increased the number of investigators working the case, and has been presenting evidence and witnesses to a grand jury. (On Friday, ABC News reported that Michael Drewniak, press secretary to Gov. Chris Christie (R), testified before the grand jury.)

Esquire isn’t the only outlet to get word of Wildstein’s interactions with prosecutors. On Sunday night, the website Main Justice reported that Wildstein “was camped at the U.S. Attorney’s office” in Newark last week meeting with prosecutors. In January, Wildstein’s attorney, Alan Zegas, said that his client would talk if given “immunity from the relevant entities.”

Main Justice also reported that Charlie McKenna, former chief counsel to Christie, met with federal investigators in mid-January. Christie announced on Dec. 19 that McKenna was leaving the chief counsel position to become CEO of the New Jersey Schools Development Authority (SDA), a position he was officially elected to by the SDA board of directors on Jan. 2. McKenna could not immediately be reached for comment by TPM on Monday.

The U.S. Attorney’s Office in New Jersey confirmed in January that it was looking into the lane closures, which caused a multi-day traffic jam in Fort Lee, N.J. in September. Democrats in the state has alleged that the lanes were closed for political reasons, and documents made public in January showed Wildstein and Bridget Kelly, former deputy chief of staff to Christie, were closely involved in the plan. Last month, a legal team representing Christie’s office released a report claiming the governor had no role in the closures, and pinning blame for the plot on Wildstein and Kelly. The lawyers who put together that report were unable to interview Wildstein, Kelly, and numerous other key figures in the scandal, and left unanswered several key questions about what happened.

Wildstein’s attorney did not immediately respond to a request for comment from TPM on Monday.