The US attorney in New Jersey is set to open an inquiry into recent controversial bridge lane closures, which critics say were engineered by New Jersey Governor Chris Christie's staff for political retribution, The New York Times reported.
The newspaper gave no further details.
Christie is a possible Republican contender for the 2016 White House race.
More top news
An Olympic silver-medallist at London 2012 has won gold after the 'winner' was stripped of his award.
Five migrants have died and more than 500 rescued after an overcrowded fishing boat capsized off the coast of Libya, the Italian navy said.
A Muslim Bataclan survivor has critised The Eagles of Death Metal frontman for saying the attacks were part of a Muslim conspiracy.