Retired Lt. Gen. Michael T. Flynn, President-elect Donald Trump's choice for national security adviser, walks through the lobby at Trump Tower on Nov. 29. (Drew Angerer/Getty Images)

The son of the top national security adviser to President-elect Donald Trump was removed from the new administration’s transition team on Tuesday after backing a bogus conspiracy theory that inspired a shooting incident in Washington, according to people familiar with the matter.

Michael G. Flynn and his father, retired Lt. Gen. Michael T. Flynn — Trump’s designated national security adviser — have both used their social media accounts to promote fabricated claims, including allegations that aides to Democratic presidential candidate Hillary Clinton were involved in a child prostitution ring.

But the younger Flynn had renewed his support for the baseless allegation even after a North Carolina man armed with an assault rifle arrived at a pizzeria in Northwest Washington on Sunday to investigate the fictitious crime. The shooter, police said, fired at least two rounds at the restaurant before he was arrested. No one was hurt.

“Until #Pizzagate proven to be false, it’ll remain a story,” Flynn posted on Twitter just hours after the shooting, referring to a conspiracy theory circulated by right-wing groups that alleged — falsely — that the Comet Ping Pong pizza restaurant served as a front for child abuse by Democratic operatives.

The tweet was the latest instance in which Flynn, 33, who has served as his father’s chief of staff and scheduler, has propagated phony news stories and incendiary views.

President-elect Donald Trump named retired Lt. Gen. Michael Flynn his national security adviser on Nov. 18, but Flynn has a history of making incendiary and Islamophobic statements that have drawn criticism from his military peers. (Peter Stevenson/The Washington Post)

His dismissal appeared to mark the first time that the Trump transition team had held one of its insiders to account for such activity. The younger Flynn had a transition team email address but is believed to have had a limited role, serving mainly as an aide to his father. The son appeared to have shut down his Facebook account, where he had also posted incendiary images and material.

The older Flynn had also lent credence to phony claims that hacked Clinton emails contained code words for child exploitation. A veteran of wars in Iraq and Afghanistan, the elder Flynn has never disavowed that claim and is poised to be among the most influential advisers in Trump’s White House.

Neither Flynn responded to requests for comment. On Tuesday evening, the younger Flynn’s Trump transition email address appeared to have been deactivated.

Philip Rucker contributed to this report.