Former CIA Director John Brennan, ex-Director of National Intelligence James Clapper, fired FBI Director James Comey and other members of the intelligence community serving under President Barack Obama were "frustrated" and took steps to make an unverified dossier on then-candidate Donald Trump appear credible, Sen. Rand Paul said Thursday.

"They wanted somehow to get the information out, this Russian dossier, that even the media wasn't publishing," the Kentucky Republican told Fox News' "Fox and Friends," quoting an unnamed source. "Nobody would publish it was so scandalous, unverifiable, was fiction. They decided we have to attach the fake dossier to an intelligence report."

His comments came after he claimed on Twitter Wednesday that Brennan had "insisted that the unverified and fake Steele dossier" be made part of a classified report to make it appear credible.

He also claimed the intelligence leaders sent "spies" into Trump's campaign to try to entrap officials into admitting they were working with Russia.

"This is a big circle...when John McCain is given the dossier, it's given to him by people who may have leaked it to our government to John McCain so John McCain can give it back to the FBI," Paul said. "It's a crazy circle all trying to justify something that wasn't true."

Paul said he wants to know when Obama found out about the dossier, and that he thinks Brennan should be called to testify before Congress as soon as possible.

Trump has said he'll declassify some documents, noted Paul, and he believes the dossier had been held by the FBI before Brennan started his group to investigate it.