Disgust and disappointment over more allegations of racism in Canterbury rugby.

A Fijian boy playing in an under-14 competition for St Thomas of Canterbury was allegedly harassed during a game against Christ's College last month.

No formal complaint has been made, but Christ's College is investigating the incident.

Christchurch Fijian Association president Vinesh Prakash said their Fijian community is quite reserved, and the incident came as a shock.

"We might not be that vocal when these things come to light, and sometimes it takes us not by surprise, but it is something we are not prepared for in the first place."

Mr Prakash said it's likely other cases of unreported racial abuse are taking place, and said he's appalled.

"We are in 2016 and everything is going forward, and we are now hearing about all these racist remarks which are unacceptable, especially in Christchurch."

Earlier this month Bronson Munro from the Waihora club was banned from all rugby for 46 weeks, after being found guilty of making racial taunts at Fijian Southbridge player Peni Manumanuniliwa​ during the club rugby final last month.

Last year, Manumanuniliwa said he was frequently the target of racial abuse.

Canterbury Rugby has encouraged others who witness racial abuse on the rugby field to come forward.