The Trump administration has employed a “rarely used” tactic to block the release of a bombshell whistleblower complaint regarding Director of National Intelligence Tulsi Gabbard and President Donald Trump’s son-in-law Jared Kushner – a complaint so sensitive that it’s currently “locked in a safe” – The Washington Post reported Wednesday.The existence of the complaint first became known to lawmakers last November when the whistleblower’s attorney sent a letter to Gabbard to accuse her office of blocking lawmakers’ access to it. That letter was reviewed by the Journal and first reported on earlier this month.The contents of the complaint remain unknown to both the public and top lawmakers, including the so-called “Gang of Eight,” a group of lawmakers who are typically briefed on matters of intelligence. One Trump administration official told the Journal earlier this month that the disclosure of the complaint could cause “grave damage to national security,” speaking with the outlet on the condition of anonymity.It was later reported that the complaint involved Kushner, and that it includes supposed details on an intercepted conversation between two foreign nationals about the president’s son-in-law.Top lawmakers have continued to push for access to the complaint, but on Tuesday, Gabbard’s office shut those requests down, and using what Glenn Gerstell, former general counsel at the National Security Agency, described as a “rarely used” tactic.“In an email to Democratic congressional staffers sent on Feb. 13 and reviewed by The Wall Street Journal, Gabbard’s office said it was unable to provide the unredacted intelligence that underpinned the complaint ‘due to the assertion of executive privilege to portions’ of the intelligence itself,” the Journal’s report reads.The citing of “executive privilege” as cause to keep the whistleblower complaint under lockdown, Gerstell said, was unusual, especially as justification to restrict access to intelligence information from the Gang of Eight.“Executive privilege is rarely used as a reason to not give information to the Gang of Eight,” Gerstell told the Journal.