RICHMOND, B.C. - A Metro Vancouver father says his son was hospitalized after being forced to take drugs at school Thursday.

Ibrahim Elburai says the boy, who has disabilities, was told he'd be physically assaulted if he didn't take a substance given to him by a group of students.

"In school, somebody had threatened him – told him that if (he didn't) take these drugs, they would hurt him. So he took the drugs," Elburai said.

Elburai says 16-year-old Hamza, who has several serious conditions including spina bifida, was given the drugs in a bathroom at McRoberts Secondary School.

It is not yet known what that substance was. Elburai says his son barely remembers anything that happened, but that he was found by concerned students after he shouted for help.

He was not in his wheelchair when he was found, Elburai said, but the group helped get him back in, then took him to the office.

Paramedics were called, and the boy was taken to hospital in an ambulance.

The school district says staff contacted Richmond RCMP as soon as it became clear what happened, but Elburai says he's angry at how the situation was handled by staff.

"The school didn't call us. The principal did not call us. The counsellors did not call us. The teachers did not call us. The police did not call us," he told CTV News Thursday.

"We had to find out from somebody else that my son is in the hospital. They should have taken this matter very seriously, because it's drugs."

In an emailed statement, Richmond RCMP said they were called to the school on Williams Road to investigate allegations a student fell ill after consuming some type of substance.

They said the investigation is ongoing and the incident is believed to be isolated. Police did not provide any further details on what is alleged to have happened.

The school district says it is working closely with the Richmond detachment to ensure the incident is fully investigated.

With a report from CTV News Vancouver's Ben Miljure