President Trump's lawyer Rudolph W. Giuliani said Friday that he has been told “off the record” that there was at least one informant for the FBI or Justice Department embedded in Trump's presidential campaign, but he admitted that he and the president do not know whether that's true.

Trump alleged in a Thursday morning tweet that during the Obama administration, the FBI placed “an embedded informant” inside his presidential campaign to improperly spy on him. Trump tweeted that if this information is true, “this is bigger than Watergate!” On Friday morning, the president tweeted this quote that he attributed to Fox Business Network anchor David Asman: “Apparently the DOJ put a Spy in the Trump Campaign. This has never been done before and by any means necessary, they are out to frame Donald Trump for crimes he didn’t commit.” Trump then added his own commentary: “Really bad stuff!”

Later Friday morning, Trump repeated his allegation that the FBI "implanted" someone in his campaign. But this time he added a caveat, "If true."

But Giuliani said in a lengthy interview with CNN on Friday morning that neither he nor the president knows whether that's true.

“First of all, I don't know for sure, nor does the president, if there really was one. We're told that,” said Giuliani, the former mayor of New York City. “For a long time, we've been told that there was some kind of infiltration. At one time, the president thought it was a wiretap.”

Giuliani admitted that the president doesn't have proof that such things are true, although he may believe them to be true, and added: “He may turn out to be closer to truth than people thought.” Giuliani said he has been told “off the record” that there was not one informant but two.

As Trump and his allies have battled to publicly identify this informant over the past two weeks, the FBI has been taking steps to mitigate the potential damage if that happens and protect other live investigations that the person has worked on, according to several people familiar with the matter. 

During the CNN interview, Giuliani also said that special counsel Robert S. Mueller III has agreed to narrow the scope of a potential interview with the president to “about two” topics. He said that he has been told Mueller doesn't plan to ask the president about the dealings of his former personal attorney Michael Cohen.

“The main focus that we want, I can tell you, simply, is Russia,” Giuliani said.

Giuliani said that he doesn't understand why the president even needs to be interviewed, other than to be trapped and forced to answer questions that could lead to perjury charges — although Giuliani quickly clarified and said that the president would not lie.

“There's nothing to lie about,” Giuliani said.