Subpoenas were served Friday to more than a dozen people with ties to embattled New Jersey Gov. Chris Christie, who is struggling to contain a burgeoning scandal over a dayslong traffic jam last year.

A New Jersey General Assembly committee investigating the episode has asked 17 associates of Christie, a Republican, to submit documents. Assemblyman John Wisniewski, the committee’s chairman, said the recipients will be called to testify before the panel in the coming weeks.

The list includes David Wildstein, a former Port Authority official who recently refused to testify before an assembly committee. Bill Stepien, Christie’s former political strategist, and Bridget Anne Kelly, Christie’s former deputy chief of staff — two Christie allies who were fired by the governor last week — also were served.

Additionally, a number of current Christie staffers — including chief of staff Kevin O’Dowd, deputy chief of staff Maria Comella and press secretary Michael Drewniak — were asked to produce materials. So was David Samson, the Port Authority’s chairman, who is regarded as one of Christie’s most influential political advisers.

Three organizations, including Christie’s gubernatorial office and his re-election campaign, were on the list as well.

The subpoenas are broad and require all relevant electronic and written correspondence to be presented.

The Christie administration has hired Randy Mastro, a high-profile defense attorney at Gibson, Dunn & Crutcher, as counsel.

The committee led by Wisniewski, a Democrat, is one of two legislative probes looking into September’s lane closures on the George Washington Bridge, an apparent act of political retribution against a Democratic mayor. The state Senate’s committee expects to issue more subpoenas next week.

Alan Zegas, an attorney for Wildstein, said his client is eager to share fresh information. But before he speaks out, Wildstein is asking state and federal prosecutors to grant him immunity.

“If he is conferred immunity, my client will fully cooperate and share his story,” Zegas said. In the meantime, he added, Wildstein “intends to fully comply with his legal obligations and will voluntarily supply documents that do not have redactions.”

Earlier this month, Wildstein released partly redacted e-mails to the Democratic-controlled Legislature regarding the bridge flap, causing a political storm and leading to the two legislative probes.

Kevin Marino, an attorney for Stepien, said Friday his client has “received the subpoena and is reviewing it.” He had no comment on whether Stepien would seek immunity before he testifies.