Transcript for Ex-Trump adviser on interview with special counsel's team

This morning we are getting a rare look inside the Russia investigation. A witness who has just been interviewed by special counsel Robert Mueller's team sitting down with our chief justice correspondent Pierre Thomas and joins us this morning. Reporter: Good morning. That's right, something truly rare. Insight from a witness just interrogated by the special counsel's office. He said he was taken aback by the intensity of investigators and the fact that they're still focusing on Russian collusion and says they are nowhere near done. Former trump political adviser Michael Caputo says he won't soon forget the grilling he says he took from two FBI agents and a prosecutor with the special counsel's team. Three hours plus, they weren't pulling any punches. At some points in time it got kind of frightening Carter Caputo said the agents knew so much about his life it scared him. They know more about what I did in 2016 than I do. They're talking about the timing of some things that happened at the campaign and at the convention. I think they're completely focused on collusion with Russia. Reporter: According to Caputo there was a lot of focus on the hack of the DNC about a Russian operative named gusafer. His stark assessment on whether Mueller is anywhere near done investigating possible collusion. I'm hoping this ends soon. But it sounds to me like they have more digging to do. Reporter: Did they give you any sense they have anything? I believe that they -- they think they're on to something. What that is, I don't know but they're not messing around. Reporter: Caputo says they peppered him with questions about his friend, the president's personal attorney, Michael Cohen, Paul manafort indicted on money laundering charges and Roger stone. The one thing he says surprised him from the interview -- It was remarkable to mow that the president wasn't brought up. Nobody with the last name trump came up at all. Reporter: Caputo said he knew Mueller's investigators would come from him because he's lived and worked in Russia but says he saw no collusion. He said all these investigations are destroying his family and he's really angry at congress. He said he told senate investigators in a hearing this week, quote, damn you to hell. George. A lot to talk about with Dan

This transcript has been automatically generated and may not be 100% accurate.