Ontario’s Special Investigations Unit has been called in to investigate an incident involving police officers and a 43-year-old man at an Oktoberfest celebration.

The SIU said Thursday that it wanted to hear from any members of the public who witnessed the incident, which occurred on Sunday, Oct. 9, at Queensmount Arena (known during Oktoberfest as Altes Muenchen Haus).

According to the SIU, the man was approached by Waterloo Regional Police officers around 10:30 p.m. and ended up being arrested.

He was taken away by police, then released from custody, and later diagnosed with a serious injury.

Witnesses are being asked to call SIU investigators at 1-800-787-8529 ext. 2314.

The SIU investigates any incident in which somebody dies or is seriously injured and police involvement is suspected.