Exeter are working closely with police after former England international Ugo Monye accused a supporter of racist abuse following Sunday's Gallagher Premiership match against Gloucester.
The 40-year-old ex-Harlequins player, who was working as a pundit, claimed he was subjected to the "most blatant racism" he has heard as he was leaving Sandy Park.
Exeter have apologised to Monye and say CCTV footage which captured the incident has been passed to Devon and Cornwall Police.
"Exeter Rugby Club have been working closely alongside Devon & Cornwall Police following the reported incident of racial abuse," read a club statement.
"We would like to say a big thank you to the huge number of people who have been in contact with the club with statements and information regarding the incident.
"We know that this behaviour is not representative of our fans.
"Exeter Chiefs have a zero-tolerance policy for behaviour of this kind, and we have acted as quickly as possible to ensure that this has been dealt with following the advice of all appropriate authorities."
Monye wrote on X, formerly known as Twitter, that one supporter running through the crowd repeatedly shouted a racist insult.
He added: "Disgraceful. Not a single person said a word, challenged or even reported it.
"He walks off after a mild scuffle and fans are now telling me 'We’re with you’ B******S you’re with me. You weren’t with me when you saw and heard the most blatant racism I’ve seen from a supporter at a live game. So fed up."
Premiership Rugby also offered support to Monye and urged anyone with information to come forward.
Its statement read: "Premiership Rugby is aware of the accusations of racist abuse suffered by Ugo Monye at Sandy Park following the Exeter match against Gloucester.
"Premiership Rugby offers our full support to Ugo Monye and we stand united with our clubs and players in the fight against racism. Racism has absolutely no place in our game or society.
"Exeter have launched a full investigation and we urge anyone with any information to come forward."
Additional reporting: PA