Attorney General William Barr has asked John Bash, the US Attorney for the Western District of Texas, to review the practice of "unmasking" before and after the 2016 election, Fox News reported on Wednesday.
According to DOJ spokesperson Kerri Kupec, US attorney John Durham was in charge of the practice, but Barr asked for a more thorough review and Bash has volunteered.
"The frequency and who was unmasking whom, and what happened after President Trump was elected as well", Kupec told Fox News' "Hannity".
Recently declassified documents revealed a number of Obama-era officials had received intelligence about Flynn's conversations during the period between President Donald Trump's 8 November 2016 election and Trump's swearing-in on 20 January 2017. The list included former Vice President Joe Biden, FBI Director James Comey, DNI James Clapper, CIA Director John Brennan, and US Ambassador to the United Nations Samantha Power.
Republicans became concerned about the number of unmasking requests made concerning Flynn, suggesting that they specifically picked officials close to Trump.
Retired Army Gen. Flynn, now 61, is one of the few Trump associates convicted as part of US state investigations into an alleged conspiracy between the US president and Russia, the so-called "Russiagate". He was prosecuted for lying to investigators about holding conversations with then Russian Ambassador to the US Sergey Kislyak and pleaded guilty in December 2017. However, in mid-January, Flynn withdrew his guilty plea because of the government's "bad faith, vindictiveness, and breach of the plea agreement", as he put it.
Allegations of US-Russia collusion prompted an almost two-year probe into the allegations. However, the final report of former Special Counsel Robert Mueller stated no evidence of collusion was found between President Donald Trump and Russia during the 2016 presidential campaign.
In early May, the Justice Department announced it was dismissing Flynn's prosecution, finding that the FBI's questioning of Flynn was not "conducted with a legitimate investigative basis", with his responses immaterial "even if untrue", but Judge Emmet Sullivan put that move on hold.