DOVER, Del. — NASCAR driver Kurt Busch has been accused of domestic assault by his ex-girlfriend, and police in Delaware said Friday they are investigating.

The Dover Police Department said that the allegations were brought to the department Wednesday. Busch’s ex-girlfriend, Patricia Driscoll, said the allegations involved an incident inside his motorhome at a race at Dover International Speedway in September, but did not go into more detail. The couple broke up about a week before.

NASCAR said it was aware of the situation and gathering information. Busch has not been charged. If he is, his case would play out after a series of high-profile cases involving prominent athletes ignited a national debate about how tough professional leagues are when allegations of abuse surface.

“It would be inappropriate for NASCAR to comment further on this matter until we have more information,” it said in a statement.

A spokesman for Stewart-Hass Racing, Mike Arning, said Busch’s team was still gathering facts about the incident and not in a position to comment.

Known as “The Outlaw” in racing circles, Busch is the 2004 NASCAR Sprint Cup champion and one of the more accomplished drivers in the series. He was in his car practicing Friday for this weekend’s race at Phoenix International Raceway in Avondale, Arizona.

Driscoll is an executive for a small Washington, D.C.-based defense consulting firm and president of the Armed Forces Foundation, a nonprofit for veterans. The couple met at a foundation dinner in 2011, and after hitting it off, Busch became a spokesman and ambassador for the foundation. The group severed its ties with him Friday.

Busch has a history of run-ins on and off the track with drivers, NASCAR officials and reporters. He was suspended by Roush Racing for the last two races of the 2005 season after police cited him for reckless driving.

A fan caught Busch on video verbally abusing an ESPN reporter during the 2011 season finale, and Busch was fined $50,000 by NASCAR after the clip was posted on YouTube. He was suspended for a 2012 race for verbally abusing a reporter.

Busch has seen a sports psychologist to learn to tame his emotions.

But with Driscoll, he appeared to have softened his image. She and her son, Houston, became fixtures in Busch’s life. The pair came across as a happy couple when Busch attempted to complete the Coca Cola 600 and the Indianapolis 500 on the same day earlier this year, a feat only a few other drivers have attempted. They welcomed reporters into her Ellicott City, Maryland, home and cameras followed them for weeks for the NBC documentary “Kurt Busch: 36.”

DENNY HAMLIN won the pole at Phoenix International Raceway, where eight drivers go into the race Sunday vying for the four spots in the championship finale.

Hamlin turned a lap at 142113 mph to put his Joe Gibbs Racing Toyota in the top starting spot. He was followed by Chase drivers Brad Keselowski and Kevin Harvick.

Joey Logano was fourth, followed by GR drivers Matt Kenseth and Kyle Busch. The top five drivers are all racing for the championship.

Gordon was seventh.

The lowest two qualifying Chase drivers were Carl Edwards in 13th and Ryan Newman in 20th.

KEVIN HARVICK does not regret shoving Brad Keselowski from behind – a move that escalated a pit road brawl between Keselowski, Jeff Gordon and their teams – but he acknowledged Friday he could have behaved differently.

But Harvick readily admitted he loves the drama that the fight created.

Harvick has always played the Machiavellian role in the NASCAR garage, and did again following Sunday’s race at Texas. Gordon was attempting to confront Keselowski on pit road when Harvick rushed in from behind and shoved Keselowski into the scrum.

It ignited a brawl that left both Keselowski and Gordon bloodied, and four Hendrick Motorsports crewmen were suspended by NASCAR.