An anonymous hacker will release troves of information about government employees working for the Federal Bureau of Investigation and the U.S. Department of Homeland Security, according to a report posted to Motherboard on Sunday. The leak may include names, phone numbers, email addresses and titles of as many as 20,000 presumed FBI employees and 9,000 presumed DHS workers.

However, the legitimacy of the records has not been confirmed by any federal agency or officials. An anonymous source did provide the records to Motherboard as proof of the breach. When Motherboard staff placed calls to some of the phone numbers listed to confirm that they were correct, several of the numbers seemed to lead to voicemails of employees matched to the numbers in the documents, while others did not.

The hacker did not state a motive for targeting employees of the FBI and Department of Homeland Security. The report also did not specify when or where the hacker planned to release the data. The source, who is identified as male in the article, told Motherboard that he acquired the records from a Department of Justice computer after hacking the email account of an employee there.

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Lately, the U.S. government has been the victim of several large security breaches. Last summer, two massive hacks of security clearances and personnel records held by the Office of Personnel Management affected 21.5 million people. Separately, about 4.2 million records of current and former federal employees were stolen from the same office.

Experts have suspected the Chinese government was behind the OPM hacks. If this newest round of records is released, the Motherboard article suggests the instigator is a lone hacker working independently.

The Government Accountability Office recently conducted an audit of the nation’s $6 billion cybersecurity network known as the “Einstein system” and found it had limited effectiveness and was only in use at a handful of the 23 agencies it was intended to protect.