Donald Trump's former campaign manager Corey Lewandowski was a guest Saturday on "Justice with Judge Jeanine" to discuss the president's accusations that the Obama administration wiretapped Trump Tower prior to the 2016 election.

Trump released a series of tweets Saturday morning comparing the alleged wiretapping to "McCarthyism."

Barack Obama's spokesman Kevin Lewis denied the allegations, and the White House released a statement Sunday saying the "politically motivated investigations are very troubling."

Lewandowski said Trump's staff likely had no forewarning whatsoever that the president would go off on his Twitter spree early Saturday.

He said the Obama administration claimed it was aware of conversations between then-Sen. Jeff Sessions and Russian ambassador Sergei Kislyak.

"What we have seen from the previous administration is they did spend time listening to conversations between then-Senator Jeff Sessions and the ambassador to Russia while he was in his U.S. Senate office." Lewandowski said. "If that were to take place, what other conversations are they listening in on?"

Trump's claims could have been in reference to a Breitbart article from Friday saying the Obama administration made two Foreign Intelligence Surveillance Court requests in 2016 to monitor Trump communications and a computer server in Trump Tower focusing on possible links with Russian banks.

"The fact that the Federal Intelligence Surveillance Act is being used to listen to a political opponent of the United States is very, very damaging," Lewandowski said.

He said there would have been huge outrage if President George W. Bush was listening in on Obama when he was a presidential candidate.

Watch the full interview with Judge Jeanine above.

Gutfeld: Trump Had His 'Most Presidential Week Yet'

WATCH: Kate McKinnon Parodies Jeff Sessions on 'SNL'

Lt. Col. Shaffer: Potential Obama Wiretapping Is 'Soviet-Level Wrongdoing'