WASHINGTON (Reuters) - A senior U.S. senator said on Friday that he expects Congress’ investigation of Russia and the 2016 U.S. election to go ahead, even after the appointment of a special counsel, and said Congress has a broader mandate that extends to financial conflicts of interest.

The U.S. Justice Department on Wednesday appointed Robert Mueller as special counsel to investigate alleged Russian meddling in the 2016 U.S. presidential campaign and possible collusion between Trump’s campaign and Russia.

“The Congress has a broader oversight responsibility than just whether crimes have been committed,” Senator Ron Wyden, the ranking Democrat on the Senate Finance Committee and a senior member of the Senate Intelligence Committee, said during a round-table meeting with Reuters.

The Senate Intelligence Committee is conducting one of the main congressional probes of the issue.

“Bob Mueller doesn’t have, for example, the same broader responsibility to get into the kind of financial entanglements that I have especially focused on,” Wyden said.

Questions remain about what contacts took place between Trump advisers and the Russians, and about Russia investments in Trump businesses.

In March, for example, the White House disclosed that Trump’s son-in-law and White House senior adviser, Jared Kushner, met executives of Russian state development bank Vnesheconombank, or VEB, in December.

Slideshow ( 4 images )

In February, Trump’s national security adviser, Michael Flynn, was forced to resign for failing to disclose the content of his talks with Sergei Kislyak, Russia’s ambassador to the United States, and then misleading Vice President Mike Pence about the conversations.

Reuters reported on Thursday that Flynn and other advisers to Trump’s campaign were in contact with Russian officials and others with Kremlin ties in at least 18 calls and emails during the last seven months of the 2016 presidential race.

“GO TO THE MAT”

U.S. intelligence agencies said Russia hacked emails of senior Democrats and orchestrated the release of embarrassing information in a bid to tip the 2016 U.S. presidential election in favor of Trump, whose views were seen as more in line with Moscow’s.

Russia has denied the allegations. Trump has dismissed suggestions of links with Moscow as Democratic sour grapes for losing the election. Trump and his aides have repeatedly denied any collusion with Russia.

Mueller’s appointment raised questions about whether he would ask Congress to step away from its investigation, or whether the dual track would complicate issues such as calling witnesses or obtaining documents.

Slideshow ( 4 images )

Some congressional Republicans have also suggested that Mueller’s appointment would lead to changes in Congress’ investigation.

Wyden said he would “go to the mat” to be sure congressional investigators get what they need. He has already put a hold on Trump’s nomination of Sigal Mandelker to the position of under secretary of the Treasury for terrorism and financial intelligence until Treasury hands over all documents related to financial dealings between Russia, Trump and Trump associates.

Wyden also said he was looking into ways to obtain documents related to dealings with Russia by Flynn. The Intelligence Committee subpoenaed Flynn for the documents on May 10. His lawyer said on Thursday that Flynn had not yet decided how to respond.

Wyden said he needed time to decide how to respond, but pledged he would do so. “We still have to know more ... about how Russia corrupted our democracy,” he said.

He said he knew that it would involve the Department of Justice.