The Central Intelligence Agency is building a large database of records on international money transfers that contains the financial and personal data of millions of Americans, say government officials with knowledge of the program.

Using the same law that the National Security Agency uses to gather and store the phone records of Americans, the CIA is building its database with transfers sent through companies such as Western Union, The New York Times reported Thursday evening. Unnamed officials revealed that the financial records program was authorized through provisions in the 2001 USA Patriot Act as well as overseen by the Foreign Intelligence Surveillance Court. Several details of the program remain unknown. But both current and former officials confirmed its existence, describing the program as highly classified.

Domestic transfers and bank-to-bank transactions are not included in the data being gathered, said several officials, but others said more than one bulk collection program has yet to come to light. “The intelligence community collects bulk data in a number of different ways under multiple authorities,” said one intelligence official.

Dean Boyd, a CIA spokesman, wouldn’t confirm nor deny if the program exists. But he did say that the agency conducts lawful intelligence collection aimed at foreign financial activities. He also asserted that the intelligence is overseen extensively.

A spokeswoman for Western Union declined to state whether the company had ever been ordered to provide bulk records on transactions. But she did say that the company obeys laws that require it to provide information. “We collect consumer information to comply with the Bank Secrecy Act and other laws,” said Luella Chavez D’Angelo. “In doing so, we also protect our consumers’ privacy.”

The Wall Street Journal reports that former government officials with knowledge of the program say it has been helpful in uncovering terrorist ties and financial patterns. If suspicious data hinting at possible terrorist activity in the U.S. is seen while a CIA analyst searches the data, the information is then passed along to the FBI by the analyst, said a former official.