The suggestion seems meant to undercut the work by special counsel Robert Mueller, who is investigating Russian interference in the 2016 election.
Despite the fact that House Republican's repeated requests for sensitive information on the origins of the Russian Federation investigation reportedly risk endangering the life of a crucial FBI informant, President Donald Trump's allies are still pushing to have the underlying facts revealed, according to a new report in the Washington Post.
"I've written a couple of columns in the last week or so pointing out there's probably no doubt that they had at least one confidential informant in the campaign", McCarthy said.
In his tweet, Trump quotes Fox Business anchor David Asman: "Apparently the DOJ put a Spy in the Trump Campaign".
The New York Times reported separately this week that at least one government informant met several times with Carter Page and George Papadopoulos, both former foreign policy advisers on Mr Trump's Republican campaign.
Trump, his attorney Rudy Giuliani and White House officials have seized on the matter in an effort to undermine the probe of special counsel Robert Mueller.
During a Thursday (Friday NZT) interview on Fox & Friends, Giuliani, a former NY mayor, called for an end to the Mueller probe.
NY attorney's racist rant was not his first (or second)
Some people also altered web pages for the man's firm to list it under the " Mexican restaurant " category, Fast Company reports. He goes on to say that he suspects the employees are in the country illegally, and his next call will be to ICE .
Trump's lawyers have been in negotiations with Mueller's team for months about whether the president would sit for an interview.
He said the legal team was "pretty comfortable, in the circumstances of this case, that they wouldn't be able to subpoena him personally".
While the Supreme Court has never definitively ruled on the subject, it appears that a sitting president could be forced to testify.
"We're trying to get [Mueller] to end this", Giuliani said.
He added: "We're going to have to look into whether we can challenge the legitimacy of the entire investigation".
President Richard Nixon at the time ordered his attorney general and deputy attorney general to fire the special counsel investigating the 1972 break-in by five men at Democratic Party headquarters at the Watergate building in Washington.