Mounties say the 35-year-old woman, who was involved in a domestic violence case, was taken into custody at the Maskwacis detachment late Sunday night.
She was found unresponsive around 3:30 a.m. Monday and attempts were made to resuscitate her, but she was pronounced dead at the hospital.
The woman's name has not been released and police have not disclosed any other details about how she died.
The RCMP's Major Crimes Unit is looking into the death, while the Alberta Serious Incident Response Team will review the Mounties' investigation.
ASIRT is the provincial watchdog agency that reviews incidents involving the death or injury of people that resulted from the actions of police, or other serious cases involving police.
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