NASCAR President Steve Phelps said Monday that those responsible will be "banned from this sport for life."
"There is no room for this at all," he said at a news briefing. "We won't tolerate it. They won't be here. I don't care who they are, they will not be here."
On Monday, the Department of Justice announced its Civil Rights Division is also investigating "to determine whether there are violations of federal law," U.S. Attorney Jay E. Town said in a statement.
The incident happened Sunday at Alabama's Talladega Superspeedway, which was hosting a Cup Series race. NASCAR said the noose was found in the garage stall of the 43 team. The 43 car is driven by Bubba Wallace, 26, the only Black driver in the Cup Series, NASCAR's highest level.
Only essential personnel were allowed in the garage, said Phelps, who said he had informed Wallace about what had happened.
"It's a difficult moment for Bubba," Phelps said. "He's handled it with the grace that he has handled everything that's happened over the last few weeks."
Wallace responded to the incident on Twitter Sunday night.
"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 said.
Wallace had pushed for NASCAR to ban the display of the Confederate flag amid calls for racial justice following George Floyd's death last month at the hands of Minneapolis police. NASCAR subsequently announced earlier this month that it was banning the presence of the controversial flag at all events.
"We are angry and outraged, and cannot state strongly enough how seriously we take this heinous act," NASCAR said in a statement on Sunday. "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 his statement Sunday, Wallace said he has been "overwhelmed" by the support from fans and that "we will not be deterred by the reprehensible actions of those who seek to spread hate."
"This will not break me, I will not give in nor will I back down," he said. "I will continue to proudly stand for what I believe in."
Ahead of the Cup Series race on Sunday, protesters were seen flying Confederate flags in a parade outside Talladega Superspeedway. A plane also flew a banner of the flag with the words "Defund NASCAR."
The race, Talladega's first and NASCAR's second overall during the coronavirus pandemic to have fans in attendance, ended up being postponed to Monday at the Lincoln racetrack due to inclement weather.
Security was stepped up at the race track for Monday's race, Phelps said.
"We want to make sure that Bubba is safe," he said. "We will firmly support as an industry, as a family and community, to make sure Bubba and everyone else in this sport is safe."
Before the 3 p.m. ET race, the words #IStandWithBubba were seen stenciled on the grass near the race track's pit road.
In a statement released Monday, Alabama Gov. Kay Ivey called on the NASCAR family to "rally around Bubba and his team as they compete today." She said she was "shocked and appalled" by what happened and will assist in finding and punishing the person responsible.
"There is no place for this disgusting display of hatred in our state," she said, adding that Wallace is a native of Mobile, Alabama. "On behalf of all Alabamians, I apologize to Bubba Wallace as well as to his family and friends for the hurt that this has caused and regret the mark this leaves on our state."
Brad Daugherty, the former NBA star and now co-owner of the NASCAR racing team JTG Daugherty Racing, said on ABC News Live Monday evening that this incident shows the "dark underbelly" of racism in the United States.
"It's a great wake-up call," the ESPN basketball analyst said.
ABC News' Joshua Hoyos, Matthew Foster, Karyn Rodus and Matt Stone contributed to this report.
This report was featured in the Tuesday, June 23, 2020, episode of “Start Here,” ABC News’ daily news podcast.
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