By Edith Honan and Ellen Wulfhorst
NEW YORK, Jan 17 (Reuters) - Twenty New Jersey officials, including top aides to Governor Chris Christie, were served with subpoenas on Friday as the state assembly begins its investigation into a massive bridge traffic jam that was apparently politically motivated.
Christie, seen as a likely Republican candidate for the White House in 2016, has denied any involvement in the so-called "Bridgegate" scandal that is dogging his second term in office.
Assembly Democrats said 20 subpoenas had gone out seeking information related to the September traffic snarl, created by the abrupt closing of access lanes to the busy George Washington Bridge, which spans the Hudson River connecting New York and New Jersey.
Among those receiving subpoenas were Christie spokesmen Michael Drewniak and Colin Reed, communications director Maria Comella, the governor's incoming chief of staff Regina Egea, and Christie's former campaign manager Bill Stepien.
The list also includes David Samson, chairman of the Port Authority of New York and New Jersey, as well as Bill Baroni and David Wildstein, two former Port Authority officials who have resigned.
Two batches of emails between top Christie aides and officials at the Port Authority of New York and New Jersey, which oversees the bridge, appeared to show the lane closures were orchestrated to punish Fort Lee's Democratic mayor for not endorsing Governor Christie's re-election bid last year.
Four days of hours-long jams left commuters fuming, and delayed school buses and emergency vehicles.
Nothing in the emails suggests that Christie had any direct knowledge of the plan to close the lanes. Christie has described himself as devastated and "blindsided" by his aides' actions.
Port Authority Executive Director Patrick Foye, who ordered the lanes reopened, said in publicly released emails that he believed the closings violated state and federal law. New Jersey's federal prosecutor has opened an investigation into the matter.
A New Jersey state Senate panel is likely to issue subpoenas next week as part of its own investigation.
"We're going to try to work together," said State Senator Loretta Weinberg.
On Thursday, the Christie administration, which says it is cooperating fully with the probes, hired outside legal counsel.