FBI agent Peter Strzok's long-awaited public testimony before US Congress has spiralled into chaos, with Republican members attempting to grill him about his extra-marital affair, derogatory text messages and the boozy meeting in London between Australia's former UK High Commissioner Alexander Downer and a former Donald Trump campaign adviser.
Agent Strzok, who led the FBI's investigation into Russian interference in the 2016 US elections before having to step down in controversy when his anti-Trump text messages were revealed, faced questions for more than 10 hours in Washington DC on Thursday.
Republicans on the House Judiciary and Oversight Committees attempted to tear him down.
Democrats defended and praised him.
There were attempts to mine new details from Agent Strzok about Mr Downer's mysterious May 2016 drinks at the Kensington Wine Rooms with Mr Trump's campaign adviser George Papadopoulos.
"You opened up the counter-intelligence investigation on 31 July," Florida Republican, Ron DeSaints, told Agent Strzok.
"Was that because of the George Papadopoulos information?"
Agent Strzok replied: "Sir, I can't get into (it)".
A New York Times investigation pinpointed the Papadopoulos-Downer drinks as the spark that began the FBI and subsequent Special Counsel Bob Mueller probe into links between Mr Trump's election campaign and Russia.
Mr Papadopoulos allegedly told Mr Downer Russia had political dirt on then presidential frontrunner Hillary Clinton.
Agent Strzok sidestepped the Papadopoulos-Downer and other potentially incendiary questions by following the advice of his FBI and personal lawyers, who sat behind him during the hearing.
"That gets into a level of detail that I have been directed to not provide," Agent Strzok said.
Mr Trump and Republicans in Congress have aggressively gone after Agent Strzok.
The president regularly cites the agent and his "lover", former FBI lawyer Lisa Page, in angry tweets.
Anti-Trump text messages Agent Strzok sent to Ms Page have been used by the president as examples of bias in the FBI and Mueller investigations.
Agent Strzok repeatedly rejected the accusation during his testimony.
Texas Democrat Sheila Jackson offered support to Agent Strzok.
"Did anything you did or say in 2016 change the fact in May 2016 George Papadopoulos was drunk in a London bar bragging about how Russians had dirt on Hillary Clinton?" Ms Jackson asked.
"Again, ma'am, without confirming whether or not that is accurate, no," Agent Strzok replied.
The hearing erupted when Texas Republican Louie Gohmert confronted Agent Strzok about his affair with Ms Page.
"I can't help but wonder when I see you looking there with a little smirk, how many times did you look so innocent into your wife's eyes and lie to her about Lisa Page?" Mr Gohmert asked.
Democrats yelled at Mr Gohmert.
"This is insane," one exclaimed.
"Do you need your medication?" another shouted.