Yahoo on Wednesday called on the U.S. Director of National Intelligence James Clapper to declassify a surveillance order sent to the company by the U.S. government. As reported by Reuters earlier this month, Yahoo had built surveillance tools to secretly scan email accounts of millions of its users in order to gather information at the behest of the government.

“At Yahoo, we are deeply committed to transparency and to protecting the rights of our users. Yahoo was mentioned specifically in these reports and we find ourselves unable to respond in detail,” the company wrote in a letter to Clapper, posted on Yahoo’s website.

According to the Reuters report — published just days after it came to light that the personal information of at least 500 million of Yahoo users was stolen in a massive data breach in 2014 — the company was asked by the U.S. government last year to build a custom software to search all of its users’ incoming emails. The report, which cited anonymous people familiar with the matter, stated that Yahoo’s actions marked the first time a U.S. internet company had agreed to search all arriving messages, instead of sifting through stored messages or scanning a few accounts in real time.

“Yahoo is a law abiding company, and complies with the laws of the United States,” the company said at the time, denying the existence of such email gathering system and labeling the Reuters report as “misleading.”

Under current U.S. laws, intelligence agencies can order phone and internet companies to release customer data, if they believe doing so is crucial to national security, and could, among other things, prevent terrorist attacks. Companies are allowed to challenge such orders behind closed doors in the Foreign Intelligence Surveillance Court.

“We urge your office to consider the following actions to provide clarity on the matter: (i) confirm whether an order, as described in these media reports, was issued; (ii) declassify in whole or in part such order, if its exists; and (iii) make a sufficiently detailed public and contextual comment to clarify the alleged facts and circumstances,” Yahoo wrote in the letter. “We trust that the U.S. government recognizes the importance of clarifying the record in this case.”