(CNN) -- A former top appointee of Chris Christie says there is evidence contradicting what the New Jersey governor has said publicly about the notorious George Washington Bridge traffic lane closures that have roiled the Republican's administration, according to the man's lawyer.
David Wildstein resigned his position at the Port Authority of New York and New Jersey in December amid allegations that Christie appointees had ordered access lanes to the nation's biggest river crossing in Fort Lee closed last year to punish that town's mayor politically for not endorsing Christie for reelection.
Wildstein's attorney, Alan Zegas, wrote on Friday that "evidence exists" contradicting Christie's recollection about the lane closures at a news conference earlier this month.
"Evidence exists ... tying Mr. Christie to having knowledge of the lane closures, during the period when the lanes were closed, contrary to what the governor stated publicly in a two-hour press conference (on January 9)," Zegas said in a letter to the general counsel of the Port Authority of New York and New Jersey, which operates the bridge and where Wildstein had worked for the governor.
Days of lane closures
The letter references the closures over a work week in September, but does not suggest that "evidence" contradicts anything Christie has said so far about his advisers at the time or any role they might have played in alleged political shenanigans.
The letter also does not suggest that Christie had any advance knowledge of the closings. Zegas also didn't disclose the evidence.
CNN Senior Legal Analyst Jeffrey Toobin said Zegas' letter is just that. "It's not sworn testimony. It's not proof," he said.
Christie said at the January news conference in Trenton about the traffic mess that he "had no knowledge of this -- of the planning, the execution or anything about it -- and that I first found out about it after it was over."
He also said he had fired a close aide, Bridget Anne Kelly, who e-mails suggest was linked to the closures. In addition to Wildstein, two other top Christie advisers left their jobs, including the man who ran his two gubernatorial campaigns.
All have been subpoenaed by a state legislative committee investigating the matter that has called into question Christie's swaggering governing style, which has resonated with Garden State voters and has him as a leading potential candidate for the Republican presidential nomination in 2016.
The U.S. Attorney's Office in New Jersey is also investigating the bridge scandal as well as allegations from the mayor of Hoboken that Christie administration officials last year conditioned Superstorm Sandy relief funds on her support for a redevelopment project backed by the governor. The officials, including Lt. Gov. Kim Guadagno, deny the assertion.
Governor's office statement
A statement released by the Christie administration said the letter written by Zegas "confirms what the governor has said all along - he had absolutely no prior knowledge of the lane closures before they happened and whatever Mr. Wildstein's motivations were for closing them to begin with."
But the statement doesn't say whether or not he knew during the week of the lane closures from September 9-13 that they had been shut down.
And a source in Christie's office told CNN's Jake Tapper that his advisers hadn't yet pinpointed when exactly he learned about the closures -- but stressed that it was after press reports surfaced and it was not before they occurred.
For his part, Christie has given different accounts of when he first learned specifically about the traffic jams, but consistently has said that it was after the lanes were reopened and only after media reports appeared.
"I think that was the first I heard of it," Christie said at a December news conference about an October 1 Wall Street Journal article. "But it was certainly well after the whole thing was over before I heard about it."
The Christie administration initially said the lane closures were part of a traffic study, which has since been called into question by e-mails suggesting key advisers carried them out.
Fort Lee Mayor Mark Sokolich told CNN he would love to know "what they mean" specifically about the lane closures, which ended when Port Authority's Executive Director Patrick Foye fired off an e-mail on September 13 ordered the lanes reopened.
"If it's Monday, that's one thing. If it's Friday late morning, that's another," Sokolich told CNN on Friday.
Panel chair not seen documents
New Jersey Assemblyman John Wisniewski, who chairs the legislative panel leading the investigation of the bridge scandal, told CNN that it has not yet received any documents supporting Wildstein's claim about the timing of when the governor knew about the lane closures.
"I am concerned as committee co-chair that Mr. [Alan] Zegas is now identifying documents that he has not provided to us," Wisniewski said. "I'd like an explanation as to why they weren't provided before he wrote this letter (that first appeared in) the New York Times," Wisniewski said.
Wildstein invoked his Constitutional right to not testify before the state legislators on the matter earlier this month.
Wisniewski, a Democrat, said what he read in the Wildstein letter "validates the skepticism that many people have had about the governor's statements on (January 9th).
A source with knowledge of the investigation said Zegas is a well-respected attorney in New Jersey who would not likely risk his own credibility on a client like Wildstein if he didn't have documents to back up his carefully worded suggestion.
Zegas' letter also challenged the Port Authority's decision to not pay Wildstein's legal expenses related to the legislative investigation.
"I would request that you kindly reconsider the Port Authority's decision," he asked.
CNN's Ashley Killough, Chris Frates and Dana Bash contributed to this report.