Michael Flynn Jr shared tweets appearing to back the Pizzagate conspiracy theory, after a man shot up the restaurant at the heart of the online rumours.
President-elect Donald Trump on Tuesday fired Michael G Flynn, the son of his top national security adviser Michael Flynn Sr, for spreading a fake news story on Twitter about Hillary Clinton that led to an armed confrontation on Sunday at a pizza restaurant in Washington, DC.
Flynn Jr's dismissal is related to tweets he made on Sunday in defence of an online conspiracy theory that led to a real-world act of violence when a man walked into the Comet Ping Pong pizzeria in the US capital with an assault rifle and opened fire.
The theory known as "Pizzagate" went viral. It alleges that a child sex abuse ring supposedly linked to Hillary Clinton had been operating out of the restaurant. Media outlets and the fact-checking website Snopes debunked the allegations, but they continued to attract attention.
A self-described "investigator" on Sunday walked into the pizzeria and fired off several rounds. Flynn Jr tweeted "Until #Pizzagate proven to be false, it'll remain a story."
CNN on Tuesday cited government sources as saying that the transition team had sought security clearance for Flynn Jr, but Trump's candidate for vice president Mike Pence denied he was part of the transition.
Pence told MSNBC's "Morning Joe" that Flynn Jr had "no involvement in the transition team whatsoever." But he later told CNN "Mike Flynn Jr is no longer associated with General Flynn's efforts or the transition team, and we're focused eyes forward."
The younger Flynn's Pizzagate tweets were far from the first time he or his father have raised eyebrows. He previously shared unfounded claims that Republican senator and former Trump rival Marco Rubio took part in drug-fuelled gay orgies, while Flynn Sr tweeted in February that "fear of Muslims is RATIONAL" and in August claimed Democratic senators voted to impose Sharia law in Florida.