Attorney General William P. Barr has appointed a U.S. attorney in Texas to scrutinize Obama-era officials who sought to identify anonymized names in government documents that turned out to be people connected to then-President-elect Trump, a Justice Department official said Wednesday.

In an interview with Fox News’s Sean Hannity, Justice Department spokeswoman Kerri Kupec said the attorney general had tasked John Bash, the U.S. attorney in the Western District of Texas, to examine the practice of “unmasking,” which many Republicans charge was abused by the previous administration to unfairly target people close to Trump.

“The attorney general determined that certain aspects of unmasking needed to be reviewed,” Kupec said. “We know that unmasking inherently isn’t wrong, but . . . can be problematic.”

Bash’s review is an offshoot of an investigation underway by U.S. Attorney of Connecticut John Durham, who was tapped by Barr to investigate the origins of the 2016 election interference probe that has overshadowed Trump’s presidency. Like Trump, Barr has been sharply critical of the 2016 investigation, which centered on the question of whether Trump’s campaign coordinated with Russia to influence the election’s outcome, and he has said the Durham investigation could produce some results in late spring or early summer.

Notably, Barr said during a news conference last week that he did not expect Durham would investigate former president Barack Obama or former vice president Joe Biden, Trump’s presumptive opponent in this year’s election.

The attorney general has appointed multiple U.S. attorneys from other jurisdictions to review work done by career prosecutors and agents in politically sensitive cases. In the case of Trump’s former national security adviser Michael T. Flynn, the U.S. attorney from St. Louis determined that Flynn’s 2017 guilty plea for lying to the FBI should be voided, because he concluded — and Barr agreed — that the Flynn investigation was unjustified.

Congressional Republicans have also vowed to investigate what they call the unmasking scandal, after the Trump administration declassified a list of Obama officials who may have received information regarding Flynn.

Unmasking is a common practice, drawn from government rules to protect privacy by withholding the names of American officials or companies mentioned in intelligence documents, particularly intercepted communications of foreign leaders. If a U.S. official wants to better understand the information in the document, they may ask to have that American’s identity unmasked.

Republicans have sought to portray unmasking as akin to leaking derogatory information about Trump associates to the media, but unmasking by itself only tells the requesting, authorized government official who a particular person is. Conservatives charge Obama-era officials may have used the unmasking procedures to inappropriately target people close to Trump, including Flynn. The president has accused the Obama administration of “spying” on the Trump campaign, and used the amorphous term “Obamagate” to stoke conservative anger.