Obama denies Trump's unsubstantiated accusation that he wiretapped phones in Trump Tower

A spokesman for former President Obama issued a strong denial to President Trump's unsubstantiated accusation that the former commander-in-chief wiretapped Trump Tower phones during the election campaign.

"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," Obama spokesman Kevin Lewis said in a statement Saturday. "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."

The former president was responding to a series of tweets Saturday morning by Trump claiming that the former president wiretapped phones in Trump Tower in New York City during the presidential campaign.

Trump offered no proof for his claims.

His accusation comes after an article ran Friday on the right-wing news site Breitbart claiming that the Obama administration obtained authorization to eavesdrop on the Trump campaign.

Trump compared the alleged wiretapping to the Watergate scandal under former President Nixon.

He also suggests the possibility of a legal case over the alleged wiretapping.

Later in the morning, Obama's former deputy national security adviser, Ben Rhodes, used Twitter to challenge Trump's claims.

"No president can order a wiretap," Rhodes, who continues to serve as a foreign-policy adviser to Obama post-presidency, said in one tweet. "Those restrictions were put in place to protect citizens from people like you."

In response to Trump's suggestion that a good lawyer could make the case that Obama tapped his phones, Rhodes tweeted, "No. They couldn't. Only a liar could do that."

ABC News has reached out to both the White House and aides to former President Obama for comment but has yet to receive a response.