WASHINGTON (Reuters) - Walid Phares, a former campaign adviser to President Donald Trump, testified to the U.S. House of Representatives Intelligence Committee on Friday in its investigation of possible Russian efforts to influence the 2016 U.S. election.

Phares did not speak to reporters as he entered the committee’s classified meeting room around 11 am EDT (1600 GMT) or when he left about four hours later.

In response to a request for comment Phares’ assistant told Reuters: “Dr. Phares is not making any comments for now.”

The House Intelligence panel does not discuss details of most of the dozens of interviews conducted behind closed doors during its months-long investigation, but it has been disclosed publicly that Phares has come under congressional scrutiny over his connections with Russia.

Senator Dianne Feinstein, the top Democrat on the Senate Judiciary Committee, wrote last month to Phares, who was a Trump campaign foreign policy adviser, asking him to turn over “documents related to Russian contacts and the Republican Party’s position on Ukraine.”

In her letter to Phares, Feinstein said she was interested in a meeting that he and two other Trump advisers allegedly held during the Republican National Convention in Cleveland in 2016 with Sergei Kislyak, then Russia’s ambassador to the United States.

On Nov. 29, when Feinstein announced her request, a Phares aide said he maintains Kislyak was just one of many foreign diplomats present at a panel discussion, which could not “fairly” be described as a meeting with Russian officials.

The Senate Judiciary and Senate Intelligence panels are also investigating Russia and last year’s election and possible collusion between Trump associates and Moscow, as is Department of Justice Special Counsel Robert Mueller.

U.S. intelligence agencies concluded that Russia sought to influence the 2016 U.S. election to help Trump win the White House. Russia denies any such effort and Trump has dismissed talk of collusion.