President Donald Trump sparked a firestorm by leveling a stunning and unsubstantiated accusation against his predecessor, suggesting Barack Obama ordered surveillance on his residence at New York's Trump Tower at the height of the contested 2016 general election — a claim that an aide to the former president flatly rejected.
In a series of pre-dawn posts on Twitter Saturday, the current president said that he just discovered that he was "wire tapped" just before the November elections, but nothing had been discovered. In blasting Obama as "sick" and sinking to "a new low," Trump invoked the specters of former President Richard Nixon and Wisconsin Sen. Joseph McCarthy.
In a statement, Kevin Lewis, a spokesperson for Obama, rejected Trump's assertion. "A cardinal rule of the Obama Administration was that no White House official ever interfered with any independent investigation led by the Department of Justice," he said.
"As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen. Any suggestion otherwise is simply false," he added.
Trump did not cite the source of his information, but the brash accusation may constitute an acknowledgement that officials at the highest levels of government were at one time probing his business and financial dealings. Last year, a few conservative-leaning publications reported that the FBI had obtained a Foreign Intelligence Service Act (FISA) court warrant—a request that would have been routed through the Justice Department but not the White House.
Trump's remarks also come in the middle of a raging controversy over potential contact his campaign and its surrogates may have had with Russian officials. Russia stands accused of having interfered in the election, which has widened a rift between Trump and the intelligence community.
On Friday, Fox's Brett Baier asked House Speaker Paul Ryan whether he was concerned "that the Obama Administration may have been surveilling members of the Trump campaign in a pretty detailed investigation during the election?"
Ryan responded by saying: "I don't think that's the case."
In response to Trump's comments, Rep. Eric Swalwell, a California Democrat who sits on the House Select Committee on Intelligence and is the ranking member on the CIA subcommittee, wrote on Twitter that the president was "not credible."
The president has spoken favorably about Russian president Vladimir Putin, while most Democrats and even some Republicans accuse Putin of having "hacked" the election. Last month, Republican Senator John McCain, who has emerged as Trump's chief intra-party antagonist, publicly rebuked the president for an interview in which he suggested the U.S. was not morally superior to Russia.
Fallout from the political firestorm forced newly confirmed Attorney General Jeff Sessions to recuse himself from Russia-related inquiries, amid questions over whether he had met with a Russian ambassador. Last month, the White House's top national security advisor, Michael Flynn, was forced to step down for similar reasons.
Last October, The New York Times reported that the FBI pursued a broad inquiry into Trump's links to Russia and Putin, but the investigation failed to yield any incriminating evidence. However, that hasn't stopped speculation from festering, particularly as Trump has repeatedly gone out of his way to praise Putin.
--NBC News contributed to this article.