British Columbia's police watchdog is investigating after a man suffered medical distress while in RCMP custody in Campbell River, B.C., and later died.

Mounties say the man was arrested at approximately 10:45 a.m. Thursday for a breach of his probation and was held in custody at the Campbell River detachment.

An on-duty guard found the man unresponsive and in medical distress at around 11 p.m., police said Friday.

"Officers provided first aid until emergency health services arrived and took over. He was transported to hospital but later died," police said in a statement.

The Independent Investigations Office of B.C. (IIO) has been notified and is investigating whether police actions contributed to the death, the RCMP said.

The B.C. RCMP said it will not make any further comments about the case, citing the IIO investigation.

INVESTIGATION FOLLOWS OFFICER-INVOLVED SHOOTING DEATH

An IIO investigation into the actions of the Campbell River RCMP was already underway after an incident last week in which two people died, including one man killed in an officer-involved shooting.

Mounties responded to a report of a homicide and potential hostage-taking at the Discovery Harbour Marina in the early-morning hours of June 13, according to the IIO.

The local RCMP and members of the Vancouver Island Emergency Response Team arrived and determined the reported hostages were safe and no longer at the scene, the police watchdog said in a statement later that morning.

Police reportedly spoke to the man who was the subject of the call and is alleged to have had a weapon, the IIO said.

"Shots were fired and the man was pronounced deceased at the scene," investigators said.

The IIO is asking witnesses to the incident to contact its reporting line at 1-855-446-8477 or via the iiobc.ca website.