The spotlight is on the Canterbury Rugby Union as it deals with another incident of alleged racism.

An investigation is underway after a complaint of racist language was made during a recent Christchurch club match.

The union says it can't comment on the specifics of what happened, as it is currently being investigated.

However it's just the latest in a string of complaints reported to the union in recent times.

The union's community rugby general manager, Tim Gilkison, said since a high profile case last year, it has focused on dealing with the problem.

He said that's leading to more incidents being reported to the union.

Mr Gilkison said there's a increasing eagerness from those in rugby in the district to stand up to racism.

"The difference here in Canterbury is that it has been brought to the union's attention through the campaign that we've launched to ask people to lodge a complaint so we can deal with these incidents."

He insisted racism in rugby is not restricted to Canterbury alone, and is "convinced that this sort of thing occurs elsewhere".

Mr Gilkison said some people get caught in the heat of the moment, while others consider it a form of sledging.

However he said whatever the reasons people gave for that kind of behaviour, it was crossing the line.