George Papadopoulos, a former foreign policy adviser to the Trump campaign and potentially a key witness in special counsel Robert Mueller’s Russia probe, told federal investigators that before the election, Donald Trump personally encouraged him to pursue a summit with Russian President Vladimir Putin, according to a new book being published Tuesday.

Papadopoulos’s account to Mueller — as reported in “Russian Roulette: The Inside Story of Putin’s War on America and the Election of Donald Trump,” by Yahoo News’ Michael Isikoff and Mother Jones’ David Corn — contradicts the public accounts of what took place at a critical meeting of Trump’s foreign policy team on March 31, 2016. It was at that meeting that Papadopoulos first informed Trump and the then candidate’s other foreign policy advisers that he had contacts in Britain who could arrange a summit between the GOP candidate and Putin.