Another disturbing racism allegation in the racing world ... Sonoma Raceway officials claim they, too, found a noose at their track over the weekend, and cops are now investigating.
According to officials at the legendary California track -- which plays host to NASCAR races annually -- a piece of twine tied in the shape of a noose was found hanging from a tree near the property on Saturday.
"To have something like that show up on our property is disgusting,” the raceway's general manager, Steve Page, told NBC Bay Area.
Page added he went to the Sonoma County Sheriff's Office over the incident ... and now they say they've launched a probe into the matter.
"We take it seriously," a spokesperson said. "That's why we're out there with the violent crimes unit. Put every effort into making an ID on this."
The troubling discovery came just one day before a noose was found in Bubba Wallace's garage down at NASCAR's event at Talladega Superspeedway in Alabama on Sunday.
In that incident, the FBI says it has taken over the investigation to find the culprits.
For Bubba's part, he shook off the hateful message to finish 14th in Monday's race ... and said afterward, "You're not going to take away my smile."
"The sport is changing ... Whoever it was, you're not gonna take away my smile."- @BubbaWallace