As part of a leak investigation into media stories about an official inquiry into the Trump administration's child separation policy at the southern border, the US Justice Department secretly issued a subpoena to gain access to details of a Guardian reporter's phone account.

The subpoena was issued by leak investigators in order to obtain the phone number of Stephanie Kirchgaessner, the Guardian's investigations correspondent in Washington. 

The move was made without notifying the newspaper or its reporter as part of an effort to find the source of media articles about a review into family separation conducted by Michael Horowitz, the Department of Justice's inspector general.

It is extremely unusual for US government officials to obtain a journalist's phone number in this manner, especially when there is no national security or classified information at stake, according to the Guardian.

The Guardian added that the move was all the more surprising because it came from the Department of Justice's inspector general's office, which is in charge of ethical oversight and whistleblower protections.

On his account, the newspaper's editor-in-chief denounced the action as “an egregious example of infringement on press freedom and public interest journalism by the US Department of Justice”.

She added: “We will be asking the DoJ urgently for an explanation for why and how this could have occurred, and for an apology. We will also be seeking assurances that our reporter’s details will be erased from DoJ systems and will not be used for any further infringements of press freedom.”

The inspector general's office of an outside government department, housing, and urban development conducted the leak investigation on behalf of the DoJ.

Its investigation focused on allegations that a DoJ inspector general's office employee leaked sensitive information to three news organizations: The Guardian, the New York Times, and NBC News.

The Guardian reported that it was the only one of the three outlets to receive a subpoena relating to one of its reporters' phone records.

It is worth mentioning that the Guardian published two sensitive reports by Kirchgaessner within the timeframe of the DoJ review into child separation covered by the leak inquiry.

On July 23, 2020, she revealed that the former deputy attorney general of the Department of Justice, Rod Rosenstein, had personally advised that migrant parents be prosecuted, regardless of the age of the children accompanying them.

Furthermore, Kirchgaessner reported on September 2, 2020, that a senior justice department official, nominated by Trump to be a federal judge, had assisted in the removal of a Texas prosecutor who had raised concerns about child separation.

On Thursday, investigative reporter Jason Leopold made public a redacted version of the Hud leak investigation report obtained through freedom of information laws. It was revealed that leak investigators had reviewed the evidence of 127 phone calls, totaling about six hours in length, with "phone numbers identified as belonging to Guardian reporter Stephanie Kirchgaessner" and another 126 phone calls totaling about six hours and 20 minutes "with a phone number identified as belonging to the Guardian generally."

The DoJ issued an "administrative subpoena" to a telecommunications company for "subscriber information to confirm that a specific telephone number belonged to the Guardian," according to the report.

It also stated that "basic subscriber information" involving "names, addresses, and length of service only" and "not the contents of communications" had been obtained.

"Zero tolerance" 

The Trump administration implemented child separation in 2018. Officially known as "zero tolerance," the policy directed federal prosecutors to prosecute undocumented immigrants entering the US illegally even if minors were present – a reversal of previous practice, which had spared families from criminal prosecution in order to keep children from being separated from their parents.

Here’s the ugly truth: The policy resulted in the separation of over 3,000 children from their parents or guardians, as well as widespread chaos in which the whereabouts of many children became unknown. 

After two years, the much-delayed DoJ inspector general's report on the practice was finally published in January 2021.

Politico reported earlier this week that a DoJ inspector general's office employee "abruptly resigned" after being questioned about the leak investigation.