"The exact circumstances of what he was doing before and during the incident that led to his death are still under investigation," he told the Seven Network.
He said Sufi was from a large devout Muslim family that had been left "extremely devastated", they had moved to Wodonga from Ballarat earlier this year.
Principal Clint Eckhardt described the incident as a "tragic accident".
"This news has had a profound impact ... and I know that our community will band together and support each other throughout this time," he said in a statement on Wednesday.
He said the school would offer support to anyone needing it over coming days.
The 5-year-old was described as happy and healthy with no prior medical conditions.
Police will prepare a report for the coroner.