Former CIA Director John Brennan said Tuesday that he saw information before he left office dealing with contacts between Russia and the incoming Trump administration that was "worthy" of further investigation.

But in an open hearing of the House Intelligence Committee, Brennan refused to describe what he saw, and declined to say whether he thinks the information showed that Trump's team was colluding with Russia.

"Did you see evidence of collusion, coordination, conspiracy between Donald Trump and Russian state actors?" Rep. Trey Gowdy, R-S.C., asked Brennan.

"I saw information and intelligence that was worthy of investigation by the bureau to determine whether or not such cooperation or collusion was taking place," he said. When asked about the nature of the information, he said all other details were classified.

"I think this committee now has access to the type of information that I'm alluding to here. It's classified, and I'm happy to talk about it in classified session," he said.

Earlier in the hearing, Brennan indicated that Russian officials were looking to cozy up to various U.S. officials in an effort to influence them, and said he was "worried" that they might be making progress.

"Having been involved in many counterintelligence cases in the past, I know what the Russians do. They try to suborn individuals," Brennan said. "And they try to get individuals, including U.S. persons, to act on their behalf, whether wittingly or unwittingly. And I was worried by a number of the contacts that the Russians had with U.S. persons, and so therefore by the time I left office… I had unresolved questions in my mind as to whether or not the Russians had been successful in getting U.S. persons involved in the campaign or not, to work on their behalf, again, either in a witting or unwitting fashion."

Brennan's answers seemed to leave the door open to the possibility that members of the Trump administration may have taken actions that could be viewed as collusion.

Brennan was CIA director under President Obama, and his Tuesday testimony came one day after former national security advisor Mike Flynn invoked his Fifth Amendment rights in an effort to limit his exposure to the Senate Intelligence Committee or other committees seeking his testimony.

Several statements in the open hearing by the House Intelligence acknowledged that the committee's investigation will likely take a different tack now that a special counsel has been appointed by the Justice Department to investigate Russia's meddling in the 2016 election. Because the special counsel would have a lead on working on and prosecuting any potential criminal activities, members of the House committee said their investigation will continue, but will have a stronger focus on the "counterintelligence" portion, meaning it will try to get a greater assessment of the scope and methods of the Russian operation.