Major crime investigators on Vancouver Island are looking into the sudden death of a man who went into cardiac arrest shortly after being taken into police custody.

Police were called by several residents to deal with an agitated man screaming on the 500-block of Charles Street in Victoria shortly after 3 a.m. Sunday.

Det. Rick Anthony said in a statement officers arrested the man after they were unable to "calm the man or get any rational response from him."

He was then handcuffed and taken into custody.

Within minutes, the man stopped breathing. Officers began performing CPR, as well as using an external defibrillator, when they discovered he did not have a pulse.

Victoria Fire and Provincial Ambulance Services arrived and took over trying to revive the man. He was taken to Royal Jubilee Hospital but pronounced dead shortly after 11:00 a.m. Sunday morning.

The Vancouver Island Integrated Major Crime Unit, along with the B.C. Coroner's Office, are now investigating.

It is believed the probe will take several weeks to complete.

The man's name will be released pending next of kin notification.