The Department of Justice has asked its inspector general to investigate possible infiltration into Donald Trump's 2016 presidential campaign.

The president demanded the investigation because he believes the FBI did more than monitor his staff for possible Russian influence. He wants to know if the Obama administration used the bureau to spy on him and his campaign.

President Trump tweeted up a storm over the weekend-- writing, "I hereby demand that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump campaign for political purposes-and if any such demands or requests were made by people within the Obama administration."

The president's tweets were in response to articles appearing in The Washington Post and The New York Times reporting that the FBI used an informant--a retired American professor living in the United Kingdom--to pass on information he learned while advising the campaign.

Hours later, the Justice Department announced it asked its inspector general to look into the matter. Deputy Attorney General Rod Rosenstein said if anyone did infiltrate the Trump campaign, the DOJ would need to know about it and then take action.

US Rep. Adam Schiff (D-CA), the ranking minority member of the House Intelligence Committee, doesn't believe the FBI had a spy in the Trump campaign...

"This claim by the president and the suggestion by Giuliani that there is a political spy embedded in the Trump campaign is nonsense and you hear it in the same terms that Trump often speaks which is 'people are saying,' or' I'm hearing,' or 'we're being told,' he said. "That's another way of saying this is patently untrue, but we'd like to spread it anyway."

President Trump has criticized the FBI and Department of Justice for months. He commented on Fox News last April saying, "You look at the corruption at the top of the FBI-it's a disgrace. And our Justice Department which I try to stay away from, but at some point, I won't."

On Fox News Sunday, Sen. Lindsey Graham (R-SC), expressed concerns about fake and unverified information used by the DOJ as evidence to obtain foreign intelligence surveillance warrants.

"I want to make sure that the FBI and the Department of Justice did not try to--in their own way try to change the outcome of the election. Did they use techniques and tactics approved by the court, or did they just make this up themselves?" Graham asked.

And as President Trump asked for an investigation, one of his lawyers Rudy Guiliani, said Special Counsel Robert Mueller told him he may wrap up the Russian Collusion investigation-at least the president's part of it by September first.

All may depend on the president and if he'll agree to a possible interview with Mueller.