Police are investigating an alleged sex attack on a woman involving up to five men at a Taupō motorsport park following a drift event.
The alleged incident occurred at an after-party following a two-day event at Bruce McLaren Motorsport Park on November 10 and 11.
Taupō police confirmed they are "investigating an allegation of a sexual nature with a number of alleged offenders".
Drift Matsuri NZ event organiser Chris Howard told the Herald he was contacted by police a day after the drift event about an alleged sexual assault.
Howard said park security had also contacted him about the alleged incident.
The event, New Zealand Spring Drift Matsuri 2018, showcased drift motorsport, and featured live DJs, an on-site R18 after-party, food trucks and a licensed bar.
Howard said he understood the interaction was between a man and a woman.
He did not know if the alleged incident involved a driver or a spectator.
Howard said he was out picking up rubbish around midnight when the alleged incident occurred during camp drinks after the event had wrapped up.
He had spoken to the woman involved.
"This is the first time anything of this nature has happened," he said.
Taupō area crime prevention manager Senior Sergeant Tony Jeurissen confirmed Taupō police were investigating the allegation.
He was unable to provide any further information.