The outbreak and subsequent impact on residents and staff is of significant concern to myself and the Government of Saskatchewan, Hindley said in the letter dated Friday.
The Saskatchewan Health Authority and Extendicare entered into a co-management agreement to address the outbreak in the centre in early December.
More than 200 infections among staff and residents were reported at the 220-bed facility.
Hindley wants ombudsman Mary McFadyen to investigate several issues, including how prepared the facility was for the virus.
The province reported 328 new cases of COVID-19 on Friday, and there were seven new deaths linked to the illness. There were also 218 people are in hospital, including 33 in intensive care.