(CNN) - New Jersey Gov. Chris Christie’s chief spokesman is due to testify on Tuesday before a legislative committee investigating a political scandal that has upended the Republican’s administration.
Michael Drewniak, who is appearing under subpoena, has kept a low profile since the scandal around traffic jams last September at the foot of the George Washington Bridge in Fort Lee broke.
An area of interest for investigators are exchanges Drewniak had with a key figure in the scandal, David Wildstein, last December shortly before Wildstein left his position at the Port Authority of New York and New Jersey.
Emails made public earlier this year show that the two, over a period of weeks, coordinated a response to media inquiries to the gridlock caused by closures of access lanes to the bridge over several days. The Port Authority oversees bridge operations.
Officials initially blamed the road mess on a traffic study. But investigators want to know whether Wildstein, and possibly others, abused their authority by closing down the lanes to punish the mayor of Fort Lee, who did not endorse Christie for reelection.
Drewniak has not been accused of any wrongdoing.
Christie has repeatedly denied knowing about the traffic mess until after it occurred. But the scandal has called into question his forceful governing style and clouded a potential presidential candidacy in 2016.
The U.S. Attorney’s office is also investigating the lane closures and has empaneled a grand jury.