Washington: A jury has convicted US President Donald Trump's adviser Roger Stone, finding the long-time Republican operative and self-proclaimed "dirty trickster" guilty on seven criminal counts of lying to Congress, obstruction and witness tampering.

The verdict, in a trial arising from investigations of Russian interference in the 2016 US election, is not only a blow to Stone but renews scrutiny on then-candidate Trump's activities at a time when he faces an impeachment inquiry that could derail his presidency.

Roger Stone is a longtime Republican provocateur. Credit:AP

Stone, a 67-year-old veteran Republican political operative and a self-described "dirty trickster" and "agent provocateur" was charged this year by Special Counsel Robert Mueller with obstructing justice, witness tampering and lying to the US House of Representatives Intelligence Committee during its investigation into Russian election interference.

Stone's colourful trial in federal court in Washington was as much about the rough-and-tumble world of politics, as it was about hair-splitting legal arguments, such as whether Stone truly lied about WikiLeaks since that website was never explicitly mentioned in the intelligence committee's publicly-stated parameters of its probe.