President Trump's former campaign policy adviser Carter Page denied any wrongdoing in an interview Wednesday with CBS News' Jeff Pegues, saying any review of his involvement with Russia is "going to be such an open and shut case."

Page gave the interview hours after Mr. Trump focused on Page in a series of tweets Wednesday morning, dismissing the "witch hunt" Russia investigation and saying Democrats "excoriated" Page. Page is among Mr. Trump's associates under scrutiny as the FBI and congressional panels investigate any ties between the Kremlin and the Trump campaign.

"I think it's going to be such an open and shut case," Page told CBS News.

Get Breaking News Delivered to Your Inbox

Well before Page joined the Trump campaign, he was named "Male-1" in an FBI case the led to the 2015 arrest of Russian spies in New York, and court papers allege the Russians tried to recruit Page, Pegues reports. Now, there are questions as to whether the Trump campaign properly vetted Page. There are also questions about whether Mr. Trump's team properly vetted Flynn, also of interest in the Russia probe, as Trump aides were reportedly aware Flynn was under FBI investigation before Mr. Trump's inauguration.

"People knew me very well going back many years. So, not directly within the campaign, but people I knew," Page told CBS News.

The FBI obtained a secret court order last summer to monitor Page's communications, because the government had reason to believe Page was acting as a Russian agent, The Washington Post reported in April. Page told CBS News at the time he was "happy to hear" about the Post's report.

"It shows how low the Clinton/Obama regime went to destroy our democracy and suppress dissidents who did not fully support their failed foreign policy," Page said in the statement at the time.

The FBI and congressional Russia investigations appear to be gaining steam.

The House Intelligence Committee on Wednesday issued seven subpoenas -- including to Flynn and Mr. Trump's personal lawyer, Michael Cohen. Cohen told CBS News he plans on cooperating.

Flynn has agreed to hand over some documents to the Senate Intelligence Committee after that committee subpoenaed his records, and fired FBI Director James Comey has spoken with Robert Mueller -- the special counsel in the FBI's Russia investigation -- and is cleared to testify before Congress. Comey is expected to discuss a conversation with Mr. Trump in which the president asked him to drop his investigation into Flynn.

Page will also be interviewed on "CBS This Morning" Thursday.