Senate investigators want to question a Moscow-based American businessman with ties to both Donald Trump and Russian oligarch Oleg Deripaska, CNN reports. The Senate Intelligence Committee has reportedly been trying to get hold of David Geovanis for months, believing he could be a key witness to Trump’s commercial and personal activities in Russia dating back to the 1990s. He is reported to have helped organize a 1996 trip to Moscow by Trump in the early stages of a plan to build a Trump Tower in the Russian capital, and is also believed to have worked for Deripaska, whose links to Trump’s 2016 Campaign Chairman Paul Manafort have been probed by investigators. The committee’s interest in Geovanis suggests it’s looking further back into Trump’s past in Russia than was previously thought. One witness has reportedly alleged in written testimony that Geovanis may be key in revealing whether or not Russia has material on Trump that could be personally embarrassing to him.