A visitor checks his mobile phone as he walks past a Samsung stand during the first day of the Mobile World Congress 2013 at the Fira Gran Via complex on Feb. 25, 2013 in Barcelona, Spain. (David Ramos/Getty Images)

The company that makes Signal, one of the most secure phone call and messaging apps in the world, said Tuesday that earlier this year it received its first federal grand jury subpoena for a customer’s communications records but only shared limited information with authorities.

San Francisco-based Open Whisper Systems told the government that it does not gather or keep most of the data that was being sought. The Signal platform does not collect or retain “metadata” on calls and messages that would indicate the times, dates and durations of communications, as well as the participants’ phone numbers.

The only data that Open Whisper gathers is the date and time an account is created and the date of the user’s last connection to Signal servers. The data was sought by the FBI in Northern Virginia as part of a criminal investigation. The subpoena was issued by a grand jury at the request of the U.S. attorney’s office in the Eastern District of Virginia.

The government says its inability to obtain even minimal data such as dates and times of calls and instant messages is hampering investigations.

Companies are almost never allowed to disclose when the government makes such requests. Open Whisper Systems’ disclosure came after the government agreed last week to lift a gag order that otherwise would have lasted a full year.

In recent years, a growing number of tech firms have pressed the government to allow them to be more transparent about the number and types of orders for customers’ data they are receiving in criminal and national security cases.

“The government is using gag orders in circumstances where it does not need them,” said Brett Max Kaufman, a staff attorney with the American Civil Liberties Union, which is representing Open Whisper Systems in the case. “It didn’t take the government much to agree that we could make all this public.”

The U.S. attorney’s office had no comment.

The push to allow companies to be more transparent about government requests intensified after disclosures by former National Security Agency contractor Edward Snowden detailed surveillance programs that relied heavily on the cooperation of tech firms.

More firms are also limiting the amount of data they harvest.

A letter from Kaufman to the FBI said that the government had also asked Open Whisper for data, such as times and dates of calls and IP logs that would reveal who a target has communicated with and when, that fell outside the subpoena’s scope. For such information it needed a court order or a search warrant, Kaufman said.