Nunes announced his new probe days after Fusion GPS - the firm behind the explosive Steele dossier - accused him of going back on his April decision to step away from the Russian Federation investigation.
House Oversight Chair Trey Gowdy (R-SC) and Judiciary Chair Bob Goodlate (R-VA) said in a joint statement that "Congress has a constitutional duty to preserve the integrity of our justice system by ensuring transparency and accountability of actions taken".
Earlier this year, Nunes temporarily stepped aside from the committee's Russian Federation investigation following a House ethics committee investigation into his handling of classified information, although he has continued to issue subpoenas for the probe, a sore spot with Democrats.
But Fusion said he has been effectively conducting a shadow investigation, and had subpoenaed the firm's bank for its financial records - a "blatant attempt to chill both speech with which Mr. Nunes disagrees and the free association of Americans working on a campaign against Donald Trump", the group argued in a court filing Friday.More news: Malaysia go down fighting to India in Asia Cup final
More news: Iran calls for NUCLEAR ACTION against USA accusing Washington of 'creating ISIS'
More news: Prince William and Kate Middleton have announced a due date
Clinton was not mentioned during the press conference as part of the Russian Federation investigation.
The Uranium One deal involved selling part of a Canadian-based mining company to the Russian nuclear corporation Rosatom, giving the company control of more than 20 percent of America's uranium supply.
David Bossie said Attorney General Jeff Sessions must appoint a special counsel to investigate the Uranium One deal, because that's the only way to get to the bottom of it.
"We're not going to jump to any conclusions at this time, but one of the things as you know that we're concerned about is whether or not there was an FBI investigation, and if so, why was Congress not informed of this matter", Nunes said.
"Seven years ago this month, I raised these objections with the treasury secretary who said they were being fully investigated and we want to see what happened to that inquiry", said King. Was there a DOJ investigation? "So that will be the start of the probe".
"Never before has a political party been so sad that it won the White House and so desperate for the other party to be President", Jesse Ferguson tweeted, in response to news of the new investigation.