The Alberta government is refusing to release information on toxic contaminants in snowpacks downwind from mountaintop removal coal mines.

Two top provincial scientists gathered the information while examining the effects of wind-borne dust from British Columbia mines on a pristine alpine lake in Alberta.

However, the details from a Freedom of Information request made by The Canadian Press were censored by Alberta Environment and Protected Areas.

The existence of the data regarding snowpack pollution has been verified by a number of sources for the news organisation.

In their investigation, the scientists discovered that coal mine dust had contaminated the lake sediments to the same degree as lakes downwind from the oilsands.

The scientists found that some carcinogenic chemicals in the lake sediments were already at levels that exceeded guidelines for the protection of aquatic life.