The secretive U.S. Foreign Intelligence Surveillance Court has issued its first order allowing the National Security Agency to collect telephone records under a new electronic spying law Congress passed last year.

According to an order from the court posted Tuesday on a website operated by the Office of the Director of National Intelligence, the court issued the order on Dec. 31.

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The order, signed by FISC Chief Judge Thomas Hogan, said the court concluded that a surveillance application, apparently submitted by the NSA, met the requirements of the USA Freedom Act, which President Barack Obama signed last year.

That law replaced an older one that allowed NSA to collect telephone "metadata" – records of American citizens' and residents' calls, including their origin and destination, when a call was placed and how long it lasted. However, U.S. intelligence officials have said the NSA did not collect the content of phone calls under this program and did not look at the data without some specific justification.

Former NSA contractor Edward Snowden revealed classified details of the collection program in 2013, and last year, Congress and the Obama administration narrowed the government's power to collect such domestic telephone metadata.

Under the new law and revised procedures, the government no longer collects bulk telephone metadata, but must request targeted information from telecom companies after obtaining authorization from the foreign intelligence court.

The identities of the telecom providers and the individuals or numbers whose metadata the NSA has targeted were redacted from the version of the court order released on Tuesday.

Hogan says in the opinion that the government was seeking "the ongoing daily production of detailed call records relating to an authorized international terrorism investigation", but does not offer further detail about the nature of the investigation.

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In his order, the judge accepts the argument that while the government was obliged to explain why targeting the telephone numbers of individuals is "relevant" to its investigation, it does not need to demonstrate the same relevance when examining numbers called from the initially targeted phones.

The judge also said that although the new surveillance law requires government agencies to promptly destroy telephone metadata that it might have mistakenly collected on U.S. persons, they sometimes can retain such data for as long as six months if they have reason to believe it could provide evidence of a crime.