A 12-year-old boy is on life-support at Winnipeg Children's Hospital, where he was rushed a few days after a tonsillectomy. (CBC)

A 12-year-old boy is in a vegetative state after having his tonsils removed at the Winnipeg Children's Hospital.

Dylan Campbell had the routine tonsillectomy in November and was released. However, about five days later, his mother rushed him back after he started coughing up blood, according to Morris Swan Shannacappo, grand chief of the Southern Chiefs Organization, an advocacy group for First Nations people in southern Manitoba.

The boy has been on life-support since then, completely dependent on caregivers.

Heidi Graham, spokeswoman for the Winnipeg Regional Health Authority, said the case is under investigation. The authority is working with family members and offering whatever support they need, she said.

The Southern Chiefs Organization is demanding an independent investigation to determine what happened and who is responsible.

"People that administer health care to the public — the people who work there — need to be held accountable," Shannacappo said.

"With the modern facilities that we have there, it's inexcusable to have such a simple operation and then have it end up in such a tragedy."

The boy's parents refuse to have him removed from life-support, insisting he will one day be able to leave the hospital, Shannacappo said.