NASCAR has launched an investigation after a noose was found in the garage of driver Bubba Wallace on Sunday.

Wallace, 26, is the only full-time black driver in NASCAR and has spoken out about racial injustice amid protests in the United States in the wake of the death of George Floyd in police custody last month.

As the GEICO 500 – held in Alabama, the state where Wallace was born – was postponed until Monday due to inclement weather, NASCAR said a noose had been found in the 26-year-old's garage.

The noose was discovered on the same day NASCAR's fledgling flag ban faced its biggest challenge. The ban took effect before last week's race near Miami, but there were only about 1,000 military members admitted into that race.

At Talladega, in the heart of the South, as many as 5,000 fans were allowed in, even though rain postponed the race until Monday and visitors were barred from the infield. No flags were spotted Sunday, but cars and pickup trucks driving along nearby roads were flying the flag and parading past the entrance to the superspeedway over the weekend. A small plane flew over the track Sunday pulling a banner with the flag and the words “Defund NASCAR.”

"Late this afternoon, NASCAR was made aware that a noose was found in the garage stall of the 43 team," a statement read.

"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.

"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."

NASCAR banned Confederate flags from its races and properties earlier this month.

After the noose was found in his garage, Wallace said he would continue to fight against racism.

"Today's despicable act of racism and hatred leaves me incredibly saddened and serves as a painful reminder of how much further we have to go as a society and how persistent we must be in the fight against racism," he wrote in a statement posted on Twitter.

"Over the last several weeks, I have been overwhelmed by the support from people across the NASCAR industry including other drivers and team members in the garage.

"Together, our sport has made a commitment to driving real change and championing a community that is accepting and welcoming of everyone. Nothing is more important and we will not be deterred by the reprehensible actions of those who seek to spread hate.

"As my mother told me today, "They are just trying to scare you." This will not break me, I will not give in nor will I back down. I will continue to proudly stand for what I believe in."