The investigation, ordered by provincial Justice Minister Ross Landry, reviewed whether Truro police followed proper procedures in the arrest and detention of Victoria Rose Paul.
The 44-year-old resident of Indian Brook, N.S., was arrested on Aug. 28, 2009, outside a Truro bar for public intoxication.
She had a stroke in jail and was taken the following day to a Halifax hospital, where she died on Sept. 5, 2009.
A previous review of the case by Halifax police found no wrongdoing.
Landry has said his decision to proceed with an investigation under the Police Act was prompted by concerns expressed by Paul's family and the native community.