​Yet another federal agency of the United States government maintained a database of phone records pertaining to Americans who were not necessarily suspected of any wrongdoing, the Justice Department has admitted.

In addition to the database of telephony metadata maintained by the US National Security Agency (NSA) and revealed to the world through classified documents via former government contractor Edward Snowden, a Justice Department official acknowledged in a court filing this week that the Drug Enforcement Agency (DEA) operated a similar system for roughly a decade.

The admission was made on Thursday by way of an official declaration entered in federal court by Robert Patterson, an assistant special agent in charge at the DEA, concerning a previous Department of Homeland Security investigation that helped authorities narrow in on a suspect charged with violating the trade embargo between the US and Iran.

In December, a federal judge said the government had to explain the "contours of the mysterious law enforcement database used by Homeland Security Investigation, including any limitations on how and when the database may be used,” according to Courthouse News Service.

On Thursday, the DEA agent did just that.

In a declaration filed in US District Court for the District of Columbia, Patterson wrote that a database existed at the DEA’s disposal that “consisted of telecommunications metadata obtained from United States telecommunications service providers pursuant to administrative subpoenas served upon the service providers under the provision of 21 USC 876, a provision of the Control Substance Act that provides law enforcement with the ability to investigate suspected drug crimes.” The DEA reportedly stopped using the database in late 2013.

“This metadata related to international telephone calls originating in the United States and calling [redacted] designated foreign countries, one of which was Iran, that were determined to have a demonstrated nexus to international drug trafficking and related criminal activities.”

The 2013 Snowden disclosures exposed how the US intelligence community has long been able to query a database of similar call records forwarded to the Justice Department for national security reasons. Only now, however, has it been revealed that the DEA administered a separate database, this one logging any case in or out of the US in which one of the parties is presumed to be in any such vaguely defined countries with a “demonstrated nexus” to drug dealing.

The DEA database, Patterson added, “could be used to query a telephone number where federal law enforcement officials had a reasonable articulable suspicion that the telephone number at issue was related to an ongoing federal criminal investigation.” An Iranian-based phone number was sucked up in the database, according to the official, and then led authorities to suspected sanction violator Shantia Hassanshahi.

“I have long believed that the government put Iran on its list of approved target countries under the Section 215 dragnet not to use for counterterrorism purposes (the terror Iran seems to have sponsored of late is largely US generated), but instead to support sanctions,” national security blogger Marcy Wheeler wrote on Friday, referring to the Foreign Intelligence Surveillance Act provision that lets the NSA collect telephony metadata in bulk. Indeed, Wheeler wrote that Patterson’s statement confirms that the US government had an entire other database, this time for the DEA, to support sanctions on Iran.

Saied Kashani, a lawyer for Mr. Hassanshahi, told The Wall Street Journal that he has attempted to have the phone evidence suppressed because the system, as described, “functions entirely like the NSA database…which is likely unconstitutional.”

“I think when Congress passed this statute they had no intention that an agency would use it to generate these vast quantities of information in a database on innocent Americans,’’ Kashani added.

American authorities detained Hassanshahi upon entering the US in January 2012 and, after examining his laptop, allegedly found evidence linking the man to having exported $6 million worth of goods that illegally ended up in Iran. Hassanshahi was charged with one count of conspiracy to violate the International Economic Emergency Powers Act and the Iranian Transactions and Sanctions Regulations.