A group of conservative House Republican are a step closer to filing impeachment documents targeting the deputy attorney general Rod Rosenstein.

The move, first reported by Politico on Friday, comes just hours after Rosenstein announced a dozen new indictments against a dozen Russian intelligence officers who targeted the 2016 US presidential election.

Members of the House Freedom Caucus have floated the impeachment idea recently, citing what they see as Rosenstein's "slow-walking" of an investigation into perceived political bias against Trump at the FBI.

For his part, Rosenstein has previously slapped down the impeachment threats, saying May, "The Department of Justice is not going to be extorted."

A group of House Republicans are reportedly ramping up their effort to impeach the deputy attorney general Rod Rosenstein.

Members of the House Freedom Caucus moved a step closer to that on Friday, around the same time Rosenstein was announcing new indictments against a dozen Russian intelligence officers who interfered in the 2016 US presidential election, Politico reported on Friday.

Republican lawmakers closely aligned with President Donald Trump had been floating the possibility of Rosenstein's impeachment for months, citing frustration with what they see as Rosenstein's slow-walking their inquiry into perceived political bias against Trump at the FBI, Politico's Rachel Bademan and Kyle Cheney wrote.

According to Politico, House Freedom Caucus Republicans could file their Rosenstein impeachment document as soon as next week.

Targeting Rosenstein, who is overseeing the special counsel Robert Mueller in the Russia investigation, could jeopardize that investigation.

One of the primary worries in that regard is the possibility that Trump would appoint a replacement deputy attorney general who is more favorable to him, or that Attorney General Jeff Sessions, who recused himself from the Russia probe last year, could re-assume oversight of the investigation.

Republicans have publicly tried to run Rosenstein through the ringer in recent weeks, grilling him and the FBI director Christopher Wray in an open hearing about investigations into both Trump and Hillary Clinton last month.

For his part, Rosenstein has previously slapped down the partisan threats. He told law-enforcement colleagues in May: "The Department of Justice is not going to be extorted."