The Californian billionaire hedge fund manager and liberal activist Tom Steyer has been a leading proponent for the impeachment of US President Donald Trump.
He told Hardtalk's Stephen Sackur that the US president should face impeachment for "the obstruction of justice".
He said: "We got 50 plus legal scholars, constitutional lawyers to come up with the criteria that he'd met to be impeached and they came up with 10 or 11 and we put them on our website but what I have been saying for the last year and a half is that Mr Trump has met the criteria for impeachment in public sight very clearly."
A two-year investigation into claims of Russian interference in the 2016 presidential election was carried out by former special counsel Robert Mueller. It concluded there was no collusion between Russia and the Trump campaign, but did not exonerate the president of an obstruction of justice.
President Trump said the investigation was "a giant presidential harassment" and that impeachment was a "dirty, filthy disgusting word".