President Trump's personal attorney Rudy Giuliani promoted a conspiracy theory about the 2016 murder of Democratic National Committee staffer Seth Rich on Twitter Monday morning.

Giuliani retweeted conspiracy theorist Matt Couch, who has already been sued by Rich's brother for defamation regarding claims he has made. Couch pointed out in the tweet that Rich was murdered in an unsolved robbery gone wrong, despite the fact that none of his possessions were missing from the scene.

“I was Shot multiple times in torso.. I worked for the DNC….” Couch tweeted, setting it up as a riddle from Rich's perspective. “They called it a botched robbery and sue anyone who investigates it..Who am I?”

Giuliani quote tweeted Couch and commented, "I'd like to know."

Rich's murder sparked conspiracy theories, claiming that he was the source of leaked Democratic emails to WikiLeaks and was then murdered by former Secretary of State Hillary Clinton or the "deep state" in order to silence him. The theory, if it were to be accurate, would mean that a whistleblower released those emails and not foreign hackers.

“I didn’t support any conspiracy theory,” Giuliani told the Daily Beast. “I raised several nagging coincidences.”

“I vaguely remember it and was asking a question about whether it was ever investigated fully,” he added. “Don’t remember if it was ever solved? Was it.”

The conspiracy theory was promulgated by Fox News and Sean Hannity in particular, but was retracted in May 2017.