Julie Lopez, whose son is in the band, said her son had been told Champion was "crossing bus C," a ritual where new band members are beaten as they walk from the back to the front of the bus.
"Everyone was talking about it," Lopez told the paper. "It was a planned event."
Police would not comment on what type of hazing may have taken place aboard the bus.
The university has had trouble with hazing in the past, with at least seven reports of hazing to campus public safety over the past decade, according to university spokeswoman Sharon Saunders.
The school has an extensive anti-hazing policy posted on its website, with punishments including suspension and expulsion.
In 2004, a former band member won a $1.8 million lawsuit against other band members over an incident in which he was allegedly beaten with paddling boards so badly that his kidneys shut down temporarily.