St Peter’s College principal James Bentley called it an “unfortunate incident” and confirmed an investigation was under way.
“St Peter’s College is taking this incident seriously and has launched an investigation into how the event unfolded,” Bentley said. 
Typically crossbars are 3m from the ground and placed between two posts 5.6m apart.
Liston College has been approached for comment.
St Peter’s College won 30-15 to retain the Dallow Cup.
First five-eighths Malakai Hafoka accounted for 15 of St Peter’s points, including a try.
Both schools are now tied on 31 points heading into the season’s final round, with the top four advancing to the playoffs.
Liston College is  fourth, with St Peter’s College sixth.
Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.