Anne Flaherty, Catherine Lucey And Jonathan Lemire, The Associated Press

WASHINGTON (AP) " President Donald Trump has accused the Justice Department of trying to frame him by planting a spy in his 2016 campaign.

Promoting a theory that is circulating in conservative circles, Trump quoted Fox Business anchor David Asman and tweeted Friday: "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."

But Trump lawyer Rudy Giuliani cast some doubt on that.

On whether there was an "informant" in the 2016 presidential campaign, Giuliani told CNN, "I don't know for sure, nor does the president, if there really was one," though he said they have long been told there was "some kind of infiltration."