Millwall Football Club and its security team are working with The Metropolitan Police and Barnsley Football Club to identify a supporter accused of racially abusing a visiting player in the immediate aftermath of Saturday's game between the two sides at The Den.
The matter will be investigated by the police and the club will co-operate fully.
Any individual found guilty of racist abuse at The Den is immediately issued with a lifetime ban and also offered the opportunity to attend Millwall's 'Fan Diversity Scheme'.
The club has a zero-tolerance policy against discriminatory abuse of any kind, highlighted by its 'Hear Hate? Don't Hesitate' campaign and complete support of all other similar initiatives.