David Wildstein is at right. Screenshot/NBC David Wildstein, the Former Port Authority Director of Interstate Capital Projects and an ally of New Jersey Gov. Chris Christie, cited his right to plead the Fifth Amendment in testimony Thursday on his role in a burgeoning George Washington Bridge scandal.

Wildstein resigned last month amid the growing controversy. His attorney filed a motion on Wednesday asking a judge to squash a subpoena compelling Wildstein to testify.

He repeatedly cited his right to plead the Fifth Amendment when asked questions by John Wisniewski, the chair of the Assembly Transportation Committee holding the hearing.

The panel of New Jersey lawmakers subsequently voted to hold Wildstein in contempt for refusing to answer questions.

A spokesman for Wisniewski told Business Insider that Wildstein's decision to invoke the Fifth Amendment came as something of a surprise — though he noted that Wisniewski and the panel was "prepared for the possibility."

Messages from Wildstein were among those included in newly released documents on Wednesday as part of state lawmakers' investigation into the closure of lanes onto the George Washington Bridge in Fort Lee, N.J., last year. Christie's opponents have accused his administration of closing the lanes out of political retribution.

Bridget Anne Kelly, Christie's deputy chief of staff, sent an Aug. 13 email to Wildstein that read: "Time for some traffic problems in Fort Lee."

"Got it," he replied.

Wildstein also mocked the concerns about school buses getting stuck in the gridlock that ensued from the lane closures.

"They are the children of Buono voters," he texted to an unidentified person, a reference to Barbara Buono, Christie's Democratic opponent in last year's gubernatorial election.

Wildstein also called Fort Lee Mayor Mark Sokolich a "little Serbian."