The incident is said to have happened in a pub after Sunderland's 1-0 defeat at Wigan on Saturday.

Furious Bent revealed on his Twitter page that his mum, Shirley, was in a busy pub in the town where dozens of Black Cats fans had come together after the loss against manager Steve Bruce's former club.

It is alleged that a man was sick of waiting at the bar to be served and shouted at the barmaid: "Don't treat me like I'm black."

Shirley Bent, who was standing close by, challenged the fan, telling him she was Darren's mother and not to speak to people like that.

Darren, 25, who has more than 22,800 people following his blog, wrote: "So we get beat by Wigan and to make matters worse my mum gets racially abused by a Sunderland fan. I won't stand for that. It's an absolute disgrace."

A spokeswoman for Sunderland AFC, said: "Behaviour of this kind is totally unacceptable to our football club."

Martyn McFadden, who runs Sunderland's fanzine, A Love Supreme, said: "Sunderland fans do not have a reputation for racism. Everyone is shocked by this."

Martyn said the person involved should be thoroughly ashamed of themselves.

A spokesman for Greater Manchester Police, who were called to the pub following the alleged incident, confirmed it was looking into the matter.

A spokesman for Northumbria Police, added: "We are working with Greater Manchester Police and Sunderland AFC in investigating this incident."

Inquiries are on going and anyone with information is asked to contact Northumbria Police on 03456 043 043.

England striker Darren Bent is gaining a reputation keeping his fans up-to-date with happenings via his Twitter page.

Some tweets that made the headlines include:

When his summer move from Tottenham to Sunderland stalled, he slammed Spurs chairman Daniel Levy, tweeting: "Do I wanna go Hull City NO. Do I wanna go stoke NO do I wanna go Sunderland YES. Sunderland are not the problem in the slightest."

He later revealed his move to the Stadium of Light was back on, telling fans he was getting off a flight to Tottenham's pre-season trip to China to sign terms with Steve Bruce's side.

Bent shocked Sunderland fans when he revealed his good start to the season – he's scored nine goals so far – was down to talking finishing with Black Cats' nemesis Alan Shearer.

He told fans how he endured every Mackem motorist's worst nightmare when his car ran out of petrol on Newcastle's Tyne Bridge.

He even had some Twitter banter with Sunderland's Olympic boxer Tony Jefferies to see who could get 10,000 followers first. Bent won.