Newly released documents reveal extensive contacts between a key aide to Rep. Devin Nunes (R-Calif.) and indicted Rudy Giuliani associate Lev Parnas.

The frequent communications between Parnas and Nunes’s aide Derek Harvey were revealed in records provided by Parnas and released Friday night by the U.S. House.

The information is particularly problematic for the GOP congressman — the top Republican on the House Intelligence Committee — because of his role in the House impeachment hearings concerning Donald Trump’s pressure on Ukraine to announce an investigation into the president’s political rival Joe Biden. Nunes participated in the hearings and strongly defended Trump, even though the records indicate he may have been involved in the operation. Nunes has denied any role in the scheme to press Ukraine to investigate Biden.

But text messages released Friday between Parnas and Harvey indicate that Nunes’s office was aware of the operation at the heart of the impeachment inquiry and that he sought to use the information Parnas was collecting. Texts show that Parnas was working last spring to set up calls for Harvey with the Ukrainian prosecutors who were allegedly providing information about former Vice President Joe Biden and his son Hunter to Giuliani, Trump’s personal attorney.