Wallace, the only black driver in NASCAR's top series, had forced the move in the wake of protests across the United States and beyond following the police killing of unarmed black man George Floyd.

Five years ago, former NASCAR chairman Brian France had tried to ban the flying of the flag at tracks, but it was not enforced and largely ignored.

With the ban now in place, it has faced opposition and there were vehicles waving the flag outside Talladega Superspeedway in Lincoln in the state of Alabama.

However, in a sinister development, a noose was found in Wallace's garage yesterday.

NASCAR responded with a strong-worded statement.

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

"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 out resolve to make the sport open and welcoming to all."

A noose symbolises the lynching of African-Americans, a weapon of racial terrorism infamously used in the United States - particularly the south - in the 1800s and 1900s.

Some lynchings still occurred even during the civil rights movements of the 1950s and 1960s.

According to the National Association for the Advancement of Colored People, 3,446 black people were lynched between 1882 and 1968 in the US.

These racist attacks were often carried out by hate groups including the Ku Klux Klan, a white-supremacist organisation.

According to ESPN's Marty Smith, Wallace did not see the noose - a member of his team noticed it first and reported it to NASCAR.

Wallace added on Twitter: "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.

"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."

NASCAR for years has looked to distance itself from the flag, often regarded as a symbol of southern pride by those who defend it.

Those opposed to the Confederate flag take issue with its pro-slavery roots, given it is an adaptation of one used by the Confederate States of America during the American Civil War.

These states seceded from the US primarily due to the northern states' stance on abolishing slavery.

Despite the Confederacy only lasting from 1861 to 1865, it continues to be a part of southern identity in many states such as Alabama, Mississippi and Georgia.

There have only been eight black drivers who have started at least one race in the NASCAR Cup Series since Wendell Scott's debut in 1961.