US-based motor-racing organisation Nascar says it is investigating after a noose was found in the garage stall of African-American driver Bubba Wallace.
Wallace, Nascar’s only full-time black driver, successfully campaigned to get the Confederate flag banned from races.
The flag has been a common sight at Nascar circuits but for many it remains a symbol of slavery and racism.
In a statement, Nascar condemned the “heinous” act at Talladega Superspeedway in Alabama.
“Late this afternoon, Nascar was made aware that a noose was found in the garage stall of the 43 team,” the organisation said.
“We are angry and outraged and cannot state strongly enough how seriously we take this heinous act. We have launched an immediate investigation and will do everything we can to identify the person(s) responsible and eliminate them from the sport.”
It added: “As we have stated unequivocally, there is no place for racism in Nascar and this act only strengthens our resolve to make the sport open and welcoming to all.”
In a statement on Twitter, Wallace, 26, described the incident as a “despicable act of racism” that left him “incredibly saddened”.
“This will not break me. I will not give in, nor will I back down,” he said.
Earlier this month, Nascar banned the Confederate flag from all races. It came amid global protests against the death of George Floyd while in Minneapolis police custody.
Wallace had called for the flag to be banned from racetracks where it had become a common sight, particularly in the sport’s southern US heartland.
“Get them out of here. They have no place for them, ” he told CNN. “No one should feel uncomfortable when they come to a Nascar race. It starts with Confederate flags.”
However, before Sunday’s scheduled racing at Talladega, a small plane flew over the track trailing a Confederate flag and a banner that read “Defund Nascar”.
Nascar executive vice-president Steve O’Donnell condemned the display on Twitter.