PlayNow is asking all players to update their account passwords as a precautionary measure.
This, after a recent incident, involving passwords stolen from other companies' sites, impacted a small percentage of the account base.
BCLC officials say they detected a suspiciously high volume of traffic on the site last Wednesday.
After reviewing the data, PlayNow identified the traffic was the result of "credential stuffing", where criminals attempt to access player accounts using email addresses and passwords previously exposed or stolen from other companies.
Credential stuffing works on the premise that people often use the same user ID and password across multiple websites.
The Office of the Information and Privacy Commissioner of B.C., the Office of the Privacy Commissioner of Canada, BC Gaming Policy and Enforcement Branch, the Manitoba Ombudsman's Office, the Liquor & Gaming & Cannabis Authority of Manitoba, the Saskatchewan Information and Privacy Commissioner and RCMP have all been notified.
BCLC operates PlayNow in BC, Saskatchewan and Manitoba.