NEXT: Trump lawyer Michael Cohen becomes target in congressional probe of Russia ties
Michael Cohen (CNN)

President Donald Trump's personal lawyer Michael Cohen has become a target in the widening probe of Russian efforts to interfere with the U.S. presidential election.

Cohen confirmed that he has been asked by House and Senate investigators to "provide information and testimony" about any contacts he had during the campaign with Russian government officials, reported ABC News.

The attorney told ABC News that he had turned down the invitation, however.

"I declined the invitation to participate, as the request was poorly phrased, overly broad and not capable of being answered," Cohen said.

The Senate Select Intelligence Committee reacted to Cohen's decision by voting unanimously to grant the chairman Sen. Richard Burr (R-NC) and ranking Democratic Sen. Mark Warner (VA) blanket authority to issue subpoenas to obtain his testimony.

Cohen's name turned up in an infamous 35-page dossier compiled by a former British spy on possible blackmail of Trump by Russian intelligence.

The unconfirmed memo claims Cohen met secretly with Kremlin officials in Prague during August to "clean up the mess" over former campaign chair Paul Manafort’s ties to the pro-Russia regime in Ukraine.

Cohen then allegedly helped arrange plans to pay off hackers and others involved in the operation and quickly move them underground in case Hillary Clinton won, according to the document.

The attorney has denied the claims made in the dossier and said he was in California at the time with his son.

Cohen left the Trump Organization after the campaign to become the president's personal attorney, and he was also named deputy national finance chairman of the Republican National Committee -- which gives him influence over how money will be given out to GOP candidates.