Robert Mueller defends Russia probe, says Roger Stone remains a felon

In an opinion piece for the Washington Post, Mr Mueller said his probe was of "paramount importance" and that Donald Trump ally Roger Stone "remains a convicted felon, and rightly so" despite the President's decision to commute his prison sentence.

Mr Mueller said that though he had intended for his 448-page report on the investigation to speak for itself, he felt compelled to "respond both to broad claims that our investigation was illegitimate and our motives were improper, and to specific claims that Roger Stone was a victim of our office".

Mr Mueller did not specify who was making the claims, but it appeared to be an obvious reference to Mr Trump, who as recently as Saturday derided the investigation as this "whole political witch hunt and the Mueller scam".

The opinion piece outlined the basis for the Stone prosecution, with Mr Mueller recounting how Stone had not only tampered with a witness but also lied repeatedly about his efforts to gain inside information about Democratic emails that Russian intelligence operatives stole and provided to WikiLeaks, which published them in the run-up to the election.

Stone was particularly critical, Mr Mueller writes, because he claimed inside knowledge about WikiLeaks' release of the stolen emails and because he communicated during the campaign with people known to be Russian intelligence officers.

"We did not establish that members of the Trump campaign conspired with the Russian Government in its activities," Mr Mueller wrote