We must respond to valid subpoenas issued by law enforcement, AT&T spokesman Mark Siegel said in an email, without commenting further. Toby Jorrin/Getty Images

For at least six years, federal drug and other agents have had near-immediate access to billions of phone call records dating back decades under a deal with AT&T that officials have taken pains to keep secret, newly released documents show.

The program, previously reported by ABC News and The New York Times, is called the Hemisphere Project. It's paid for by the U.S. Drug Enforcement Administration and the Office of National Drug Control Policy, and it allows investigators armed with subpoenas to quickly mine the company's vast database to help track down drug traffickers or other suspects who switch cellphones to avoid detection.



The details of the Hemisphere Project come amid a national debate about the federal government's access to phone records, particularly the bulk collection of phone records for national security purposes.

Hemisphere, however, takes a different approach from that of the National Security Agency, which maintains a database of call records handed over by phone companies as authorized by the USA Patriot Act.

"Subpoenaing drug dealers' phone records is a bread-and-butter tactic in the course of criminal investigations," Justice Department spokesman Brian Fallon said in an email.

"The records are maintained at all times by the phone company, not the government. This program simply streamlines the process of serving the subpoena to the phone company so law enforcement can quickly keep up with drug dealers when they switch phone numbers to try to avoid detection."

The Associated Press independently obtained a series of slides detailing Hemisphere. They show the database includes not just records of AT&T customers, but of any call that passes through an AT&T switch.

The federal government pays the salaries of four AT&T employees who work in three federal anti-drug offices around the country to expedite subpoena requests, an Obama administration official told the AP on Monday.

The official spoke on the condition of anonymity because he or she was not authorized to discuss the program, and said that two of the AT&T employees are based at the High Intensity Drug Trafficking Area office in Atlanta, one at the HIDTA office in Houston, and one at the office in Los Angeles.

The Hemisphere database includes records that date back to 1987, the official said, but typical narcotics investigations focus on records no older than 18 months.

