The Alberta Serious Incident Response Team is investigating a woman's death which police say happened after she'd been released from hospital into their custody.
The Lethbridge Police Service says the 31-year-old was arrested late Friday in connection with an aggravated assault, and they say she was "highly impaired by unknown substances" at the time.
Police say that after an assessment by EMS, she was transported to Chinook Regional Hospital and remained there under the care of medical staff throughout most of Saturday.
She was released back into the custody of police, and was placed in a holding cell at the police station where she was later found unresponsive.
Police say attempts by officers and EMS failed to revive her, and she was pronounced dead.
Lethbridge police say ASIRT, which investigates incidents or complaints involving serious injury or death that may have resulted from the actions of a police officer, is now handling the investigation and the force won't be commenting further.