Christchurch Club winger Sake Aca was taunted to tears on Sunday following a match against Lincoln University.
The Fijian asked his coach to remove him from the field when spectators began yelling racial abuse at him.
Police have confirmed they have received a complaint from Canterbury Rugby Union's general manager of community rugby.
The complaint was made after a meeting between rugby officials.
Detective Senior Sergeant Greg Cottam said police are speaking to players involved as well as spectators.
"It's unacceptable that in this day and age anyone is subjected to any form of discrimination, particularly racial abuse, and I urge anyone responsible to show some moral courage and come forward to discuss and resolve the matter."
Christchurch head coach Daniel O'Brien said several of his players had been abused throughout the game but Aca was very upset.
"I spoke to him as he came off the field and he was in tears and finding it very difficult to speak," he said.
Mr O'Brien said Aca went home early from the match to spend time with family.
The Canterbury Rugby Football Union is also helping police to find out who the comments came from.
"We're keen to stamp it out ... [and are] pulling out all the stops to see whether we can identify who it was ... through any sources that we've got, like footage of that fixture," general manager Tim Gilkison said.
Anyone with information relating to this alleged incident can contact Constable Luke Vaughn on 03 363 7400 or anonymously by contacting Crimestoppers on 0800 555 111.
