The B.C. Conservation Service executed search warrants at the Mount Polley mine and the Vancouver offices of its owner Imperial Metals Tuesday night, in relation to the spill of 25 million cubic metres of waste from the mine's tailings pond last August.

Insp. Chris Doyle with the conservation service said the search warrants were issued to support a joint investigation by the B.C. Conservation Service, the RCMP, Environment Canada and Fisheries and Oceans Canada.

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An investigator seizes evidence from the offices of Imperial Metals in downtown Vancouver. (CBC)

"The investigation primarily focuses on offences related to the Environment Management Act and the Federal Fisheries Act, but is not limited to these acts," he said.

Imperial Metals owns and operates the Mount Polley open pit copper/gold mine located in B.C.'s Cariboo region near the small town of Likely.

Last week, an independent investigation blamed the failure of the tailings pond on poor design, which didn't take into account the underlying instability of the earth below — a situation investigators likened to a "loaded gun."

Imperial Metals said at the time the construction of the tailings pond was "at all times carried out in accordance with design criteria provided by engineers and approved by the Ministry of Energy and Mines."

As the warrants were being executed, they issued a short statement downplaying the development.

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B.C.'s Minister of Energy and Mines Bill Bennett says the government will take action to prevent future tailings dam failures. (CBC)

"The Company understands warrants to be a normal means of investigation, and cooperated fully with the regulatory authorities," the statement said.

First Nations Leaders in B.C. called a news conference earlier in the day urging the provincial government to implement all the recommendations made in the government review.

Grand Chief Stewart Phillip of the Union of B.C. Indian Chiefs says there is a massive need for reform in the mining industry, and the independent panel's report offers a framework for change that must be implemented in its entirety.

The investigation made several recommendations to improve the safety of tailings dams, including updating the way they are designed, monitored and regulated in B.C.

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Investigators say the dam was built on a weak layer of glacial deposits.