Harvard law professor Alan Dershowitz insisted he has information showing that President Barack Obama "personally asked" the FBI to investigate someone "on behalf" of billionaire financier George Soros.

Speaking with Breitbart News in an interview that aired Sunday on SiriusXM, President Trump's impeachment attorney weighed in on the president's tweets about the case against his longtime associate Roger Stone and the Department of Justice's decision to scale back Stone's recommended sentence. Dershowitz defended the DOJ's move, which resulted in more than a thousand former department officials calling on Attorney General William Barr to resign.

"There was a lot of White House control of the Justice Department during the Kennedy administration, and I don't think we saw very many liberal professors arguing against that," he said.

"I have some information as well about the Obama administration, which will be disclosed in a lawsuit at some point, but I'm not prepared to disclose it now, about how President Obama personally asked the FBI to investigate somebody on behalf of George Soros, who was a close ally of his," he continued, without naming a specific target.

Dershowitz added, "We've seen this kind of White House influence on the Justice Department virtually in every Justice Department. The difference is this president is much more overt about it. He tweets about it. President Obama whispered to the Justice Department about it. And, I don't think these 1,000 former Justice Department officials would pass the shoe-on-the-other-foot test. Maybe some of them would, but a good many of them wouldn't."

Soros, who has donated large sums of money to Democratic campaigns and social causes, has been at the center of right-leaning conspiracy theories for years, including claims that he is part of a liberal plot to control the world. Such theories have been dismissed by the Anti-Defamation League as anti-Semitic.

In December, the organization condemned unsubstantiated claims about Soros after Rudy Giuliani, the president's personal lawyer, called the mega-donor "hardly a Jew" and pushed conspiracies that he was attempting to undermine Trump on Ukraine.

"For decades, George Soros’ philanthropy has been used as fodder for outsized anti-Semitic conspiracy theories insisting there exists Jewish control and manipulation of countries and global events," the group wrote. "Mr. Giuliani should apologize and retract his comments immediately, unless he seeks to dog whistle to hardcore anti-Semites and white supremacists who believe this garbage."

Soros's Open Society Foundation also blasted Giuliani's comments as part of his "toxic campaign of misinformation and falsehood."

When pressed on his remark about Obama, Dershowitz, who is Jewish, teased details that he said would come to light "in the near future" and claimed to have a witness report on the incident.

"That's going to come out in a lawsuit in the near future, yeah. That is not unusual. People whisper to presidents all the time; presidents whisper to the Justice Department all the time. It's very common; it's wrong, whoever does it — but it's common, and we shouldn't think it's unique to any particular president," he said. "I have in my possession the actual 302 [witness report] form which documents this issue, and it will at the right time come out, but I'm not free to disclose it now because it's a case that's not yet been filed."