The CIA has a secret, undisclosed data repository that includes information on Americans, two Democratic senators on the intelligence committee said,  AP reported.

While neither the CIA nor lawmakers have disclosed details about the data, the senators argued that the CIA has long withheld details about the program from the public and Congress.

Senators Ron Wyden of Oregon and Martin Heinrich of New Mexico sent a letter to top intelligence officials demanding they disclose more details about the program. Wyden and Heinrich said the program operates  “outside the statutory framework that Congress and the public believe govern this collection.”

“CIA recognizes and takes very seriously our obligation to respect the privacy and civil liberties of U.S. persons in the conduct of our vital national security mission,” Kristi Scott, the agency’s privacy and civil liberties officer, said in a statement. “CIA is committed to transparency consistent with our obligation to protect intelligence sources and methods.”