WASHINGTON (REUTERS) - United States Attorney-General Jeff Sessions has become the latest senior Trump administration official to hire a private attorney, a Justice Department spokeswoman said on Tuesday (June 20).

Sessions has retained Washington-based lawyer Charles Cooper, whom spokeswoman Sarah Isgur Flores described as a long-time friend of the former senator.

She did not say when Cooper was hired or whether he would be Sessions' defence lawyer in the federal probe into alleged Russian interference in last year's presidential election and possible collusion by Trump's campaign team.

Cooper was present at Sessions' confirmation hearing and again when he testified before the Senate Intelligence Committee earlier this month.

Sessions recused himself from the Russia investigation in early March, shortly after news reports surfaced of his previously undisclosed contacts with Russian Ambassador Sergei Kislyak.

He has since come under further scrutiny for his role in the firing of former Federal Bureau of Investigation Director James Comey in May. Comey accused the president of dismissing him to undermine the investigation into ties between the Trump campaign team and Russian officials.

During his testimony before the Senate committee, Sessions angrily denied any wrongdoing.

Trump, Vice President Mike Pence and senior adviser Jared Kushner have also hired attorneys as special counsel Robert Mueller, appointed after Comey's dismissal, leads the Russia investigation.