Police are investigating an alleged assault on an 11-year-old girl by one of the competitors in Saturday's Motatapu events.
Acting Sergeant Jason Reid said the father of the girl reported the incident to police at 2.20pm on Saturday.
The pair were walking across a bridge over the Arrow River when a runner "has pushed the 11-year-old ... upsetting her and causing her to cry".
Acting Sgt Reid said her father was "quite angry" about it and had contacted both Queenstown police and Motatapu officials.
"Obviously, it's someone who takes his racing a bit seriously."
Acting Sgt Reid said the incident might have been accidental, but if the runner had intentionally decided to shove the girl rather than "scoot around her", police could lay a charge of common assault.