The New Jersey legislative committee investigating traffic jams orchestrated by Chris Christie’s aides plans to start calling people who work for him to testify beginning next month — and it hasn’t ruled out asking to hear from the governor himself.

Assemblyman John Wisniewski, who co-chairs the panel, would not specify who might be called, but he said no one has been excluded, including the governor.

Wisniewski said it is “a possibility but not a certainty” that the governor would be asked to testify under oath. He said the investigation is not far enough along to decide whether Christie’s testimony will be sought.

The governor’s office didn’t return a message for comment.

Wisniewski said the committee is trying to find out why former Christie aide Bridget Kelly sent an email message to David Wildstein saying, “time for some traffic problems in Fort Lee.” Wildstein is a former executive at the Port Authority of New York and New Jersey.

The committee also wants to know how Wildstein, who replied to the message, knew what she meant.

The email set in motion lane closings near the George Washington Bridge in September that created gridlock in the town at the base of the heavily traveled span between New Jersey and New York, apparently to retaliate against the mayor, who did not endorse Christie. A review commissioned by Christie and released three weeks ago cleared the governor of wrongdoing. It placed the blame on Kelly and Wildstein, who was forced to resign in December.

Wisniewski told The Associated Press on Wednesday that the panel would not call anyone whose testimony might interfere with a federal criminal investigation. That presumably would rule out Kelly and Wildstein — whose lawyers say they are willing to testify if granted immunity from prosecution — and perhaps other former Christie associates caught up in the scandal.

The legislative panel previously issued 28 subpoenas to people and organizations close to Christie for emails and text messages related to the lane closings. People will be called to testify based on contents of the tens of thousands of documents the committee received, as well as notes from 75 interviews conducted by Gibson, Dunn & Crutcher, the New York law firm Christie’s office hired to conduct an internal review.

Kelly and Bill Stepien, who managed both of Christie’s gubernatorial campaigns, invoked their Fifth Amendment right against self-incrimination and refused to turn over documents. A Superior Court judge agreed. The legislative committee is considering an appeal.

The scandal has been a major distraction for Christie as he contemplates a 2016 run for president.

He cut ties with Stepien after picking him to run the state Republican Party and naming him as a consultant to the Republican Governors Association, which Christie heads. Stepien, who was believed to be in line to run any national Christie campaign, knew about the lane closings but not the political reason behind the plot, Christie’s report found.

In all, five Christie loyalists have lost their jobs amid the scandal that has overshadowed the 51-year-old governor’s second term.

(AP)