Alberta's police watchdog has released more information from an investigation into the death of a man that occurred earlier this month while he was being placed in the custody of the Calgary Police Service.

A suspect who died while in police custody earlier this month was unarmed when he was tackled and punched by a group of Calgary officers, the province's police watchdog said Wednesday.

Wells died Sept. 17 in an incident at a southeast Calgary hotel when a physical altercation resulted in police applying restraints and medics sedating him. Wells was unresponsive after being restrained and sedated and was declared dead at the scene.

Calgary police tackled, punched and deployed "various uses of force" on an unarmed man who died in a police altercation earlier this month, the Alberta Serious Incident Response Team (ASIRT) said Wednesday.