The chairman of the Senate Select Committee on Intelligence is investigating whether comments made by presidential candidate Ted Cruz during Tuesday night's debate contained classified information.

"The question had been raised, therefore I asked my staff to look at it and see if there was any validity to it. Anytime you deal with numbers, and I think it dealt with numbers, the question is, is that classified or not?" U.S. Senator Richard Burr told reporters on Wednesday, as quoted by Politico.

Burr's comments followed a tweet from Burr's spokeswoman, Becca Watkins, who tweeted during Tuesday night's Republican debate that "Cruz shouldn't have said that."

The controversy centers on a comment made by Cruz during an exchange with Senator Marco Rubio about the National Security Agency's surveillance programs. "[Rubio knows] that the old program covered 20 percent to 30 percent of phone numbers to search for terrorists. The new program covers nearly 100 percent," he said.