A terrifying gun threat made against Lil Xan earlier this month -- that triggered a concert cancellation -- is now the subject of a criminal investigation ... TMZ has learned.
Law enforcement sources tell us cops are investigating a series of threats made against Xan earlier this month. We're told it centers around videos and photos posted by St. Louis rapper VladHQ that show him with multiple firearms and calling out Xan.
One disturbing video shows Vlad spraying bullets into a lake, calling Xan a "bitch" and asking for "smoke" at his scheduled Oct. 10 concert at The Pageant.
He also posted a photo of himself with what appear to be three AK-47s, with a caption that read ... "hi Lil Xan see ya later at your show."
Like we told you ... Xan went on to cancel his St. Louis show after the images surfaced, which police are clearly taking seriously.
Our sources say no arrests have been made, nor have any warrants been issued.
Vlad and Xan's beef appears to stem from a dispute over money.