TORONTO (Canadian Press) -- Health Canada is warning that taking the diabetes drug Actos may increase one's risk of developing bladder cancer.

The department put out the warning today with the drug's manufacturer, Takeda Canada, Inc.

There have been concerns for awhile that Actos users may be at a higher risk of developing bladder cancer and Takeda has been conducting a 10-year study to see if that's true.

Health Canada says a report at the half-way mark of the study suggests that taking Actos for longer than 12 months increases the risk of developing bladder cancer.

People who weren't using the drug developed bladder cancer at a rate of about seven cases in every 10,000 people, while there were 10 cases per 10,000 people among the people using the drug for Type 2 diabetes.

The statement says the risk appears to be highest for people who took the drug for the longest duration or at the highest dosages, but it isn't possible to rule out a risk even after short-term use.

(c) The Canadian Press, 2012