TRENTON The lawmaker leading a legislative investigation into why an appointee of Gov. Christie ordered lanes approaching the George Washington Bridge closed in September said additional subpoenas were likely.

Assemblyman John Wisniewski said his office was wading through as many as 5,000 documents provided by the Port Authority of New York and New Jersey and its top two state appointees.

Wisniewski told the Associated Press on Monday that the documents, the result of subpoenas issued this month, tell part of the story, but others may be needed to fill in the gaps.

Two approach lanes were closed without warning, causing gridlock at the mouth of the span in Fort Lee. They were allowed to remain closed for four days until Port Authority executive director Patrick Foye ordered them reopened.

Democrats have suggested that the closings were carried out by a loyalist of Christie because Fort Lee's mayor declined to endorse the governor for reelection.

The governor has denied it. His top two deputies at the Port Authority - childhood friend David Wildstein, who decided to close the lanes, and former State Sen. Bill Baroni - have resigned. Both have retained lawyers.

Wisniewski, who heads the Assembly transportation committee, said he was trying to determine how high up the chain of command the authorization went and how such an abuse of power could have occurred.

Wisniewski was granted subpoena power to investigate the Port Authority before the latest scandal broke, but he will lose that authority when the Legislature reorganizes Jan. 14.

He told the AP he planned to prefile paperwork to renew his authority to subpoena documents and witnesses to continue the investigation.

He needs approval by a simple majority of 41 votes in the Assembly, which could come easily in a chamber of 48 fellow Democrats.

The authority's inspector general and a West Virginia senator are leading other investigations into the lane closings, which Christie has called "not that big a deal."