The Assembly committee will have subpoena power and a special counsel appointed to it.
The probe has already revealed that high-ranking officials in Gov. Chris Christie's administration were involved in ordering the closures. The scandal threatens to undermine Christie's second term and his chances at a presidential run in 2016.
Christie has apologized but denied involvement. He has fired a top aide and cut ties with a campaign adviser. A key lawmaker said last week that both could receive subpoenas soon.
Christie is scheduled to deliver his State of the State address on Tuesday.