Former New York City Mayor Rudy Giuliani (R) said Friday a “bombshell” has not yet dropped on New Jersey Gov. Chris Christie (R) in the George Washington Bridge scandal. 

Giuliani branded as too ambiguous the letter from a port authority official released Friday claiming there is evidence Christie knew about lane closures on the bridge while they were occurring last year.  

“I'm not sure it is a bombshell, Wolf,” he told Wolf Blitzer on CNN. 

“It is a statement with a lot of ambiguity — some good for the governor, some that creates questions. The part that is good — it’s clear the governor didn't know about it beforehand, right? The question is when did he find out about it.”

The New York Times obtained a letter Friday from the lawyer of former Port Authority official David Wildstein, who resigned after it was revealed he helped order the lane closure that blocked traffic for days. 

The letter alleges evidence that Christie had knowledge of the closures during the incident and that Wildstein could disprove other statements made by the governor. 

“Mr. Wildstein is very much wanting to get immunity from the government,” Giuliani said of the letter. “And I suspect if Mr. Wildstein had a smoking gun — something you could describe really, honestly as a bombshell — the government would have given him immunity.”

Giuliani, a strong defender of Christie throughout the scandal, said the governor would eventually have to go before the U.S. attorney to answer question in the probe. 

It could end up helping Christie, Giuliani said. 

“I don't think it would be good for anybody if the governor weren't eventually questioned,” he said. “The best result for Chris Christie here is that he is cleared. If he were cleared without any kind of full and complete investigation, then his political opponents would use it against him.”

If Christie is cleared, that will once against make him a viable candidate in 2016, Giuliani said. 

Giuliani predicted, however, that Christie’s testimony would not come until the end of the probe.

“Generally, you don't want to talk to the top guy until you have talked to everybody else,” he said. Adding, “you want to get to the end of the process before you go after the governor.”