The FBI has not yet needed to get a warrant before using its drones for surveillance, a bureau official told Sen. Rand Paul on Monday.

In a letter sent to the Kentucky Republican, Stephen Kelly, assistant director of the Office of Congressional Affairs, said warrants were not required because the surveillance took place place over public space, “and there was no reasonable expectation of privacy.”

The letter responded to Paul’s request for information about domestic drone surveillance. In June, former FBI Director Robert Mueller acknowledged to lawmakers that the agency has employed the use of drones over U.S. soil. A letter sent from the FBI last week to Paul indicated that the agency has used drones 10 times since 2006.

Paul said in a statement Monday that he disagrees with the FBI about the warrants, but since the agency replied to his request for more information, he released his hold on Obama’s pick to head the FBI. The Senate cleared the nomination of James Comey later Monday on a vote of 93-1, with Paul voting “no” and two senators voting “present.”

“The FBI today responded to my questions on domestic use of surveillance drones by saying that they don’t necessarily need a warrant to deploy this technology,” Paul said in a statement. “I disagree with this interpretation. However, given the fact that they did respond to my concerns over drone use on U.S. soil, I have decided to release my hold on the pending FBI director nominee.”