Two New Jersey State Police troopers were suspended without pay Monday after being accused of escorting a high-speed caravan of sports cars allegedly driven by business executives and NFL running back Brandon Jacobs.

The suspensions stem from a March 30 convoy of about two dozen Lamborghinis, Porsches, Ferraris and other high-performance vehicles driven down the Garden State Parkway. One witness who complained to authorities said the cars were traveling in excess of 100 mph and dubbed the caravan "death race 2012."

New Jersey Attorney General Jeffrey Chiesa, whose office includes the State Police, said the caravan wasn't authorized and had the potential to injure other motorists. "We will not tolerate any conduct by a member of the State Police that puts the public in jeopardy," Mr. Chiesa said in a statement.

New Jersey State Police routinely escort caravans of vehicles—from funeral processions to charity motorcycle events—down Garden State highways when asked for assistance. But the episode in March has ignited new scrutiny of the practice and caused a high-profile headache for state law enforcement.

As authorities announced a separate probe of a 2010 trip of performance cars escorted by troopers, Gov. Chris Christie weighed in on the matter Monday, calling the March escort "a dumb thing to do." Other elected officials also issued rare criticism for the State Police.