Director of National Intelligence James Clapper testifying before the Senate Intelligence Committee during the annual open hearing on worldwide threats on Capitol Hill in Washington on March 12, 2013. (Susan Walsh/AP)

Sen. Rand Paul (R-Ky.) said Tuesday that Director of National Intelligence James Clapper lied to Congress during a March hearing.

"What I'm saying is that the Director of National Intelligence, in March, did directly lie to Congress, which is against the law," Paul said on CNN, according to a transcript. "He said that they were not collecting any data on American citizens."