Christie, a pugnacious, budget-cutting Republican, is widely mentioned as a potential GOP candidate for president.
Democrats called for an investigation Wednesday. GOP leaders, meanwhile, were mute, with no one immediately coming to his defense.
"Gov. Christie obviously doesn't include himself in his hollow call for shared sacrifice," Democratic state Assemblyman Paul Moriarty said as he called on the governor to publicly detail his use of state police helicopters and reimburse the taxpayers for any personal or political trips. "Gov. Christie must learn that taxpayers cannot afford his helicopter joyrides."
While state police helicopters cost $2,500 an hour to operate, State Police Superintendent Rick Fuentes said that giving Christie a lift did not cost taxpayers anything extra because the pilots need to put in flying time anyway to keep their skills sharp.
Christie, his wife, Mary Pat, and an aide arrived by helicopter just before Tuesday night's game in Montvale to watch their oldest son, Andrew. The couple stepped off the aircraft and into a trooper-driven car that drove them 100 yards to the bleachers. They watched the game surrounded by state troopers.
Paul Loriquet, a spokesman for the New Jersey attorney general's office, said that as the state's chief executive, Christie can use the helicopter "at any time for any purpose" and that it is up to the governor to decide if he should reimburse the state for personal use.
Christie, a former federal prosecutor who indicted politicians for misusing public money, has been urged by GOP loyalists to run for president. Christie left the ballgame to go to a dinner at the governor's mansion in Princeton with a delegation of Iowans who tried - unsuccessfully - to persuade him to mount a White House bid.
The Associated Press contributed to this report.