The share price of Imperial Metals Corporation fell more than six percent in the first two-and-a-half hours of trading this morning on news that conservation officers had visited the company's Vancouver head office.

The stock price was $8.62 at 9 a.m., off 61 cents from yesterday's closing price of $9.23.

Imperial Metals issued a terse announcement on its website yesterday confirming that "search warrants were executed by Conservation and Fisheries officers today at the Company's head office and at the Mount Polley mine".

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

Last August, a tailings-dam wall collapsed, sending approximately 10 million cubic metres of water containing toxic mine waste into Hazeltine Creek and Polley Lake. It contaminated the water supply in the town of Likely.

The largest shareholder in Imperial Metals Corporation is Calgary billionaire Murray Edwards. As of November 30, companies that he controlled held 36 percent of the stock, with Fairholme Capital Management LLC listed as the second largest shareholder with 16.9 percent.

Edwards, a director and former chairman of Canadian Natural Resources, organized a fundraiser in 2013 to help Premier Christy Clark's reelection bid, according to a story last year in the Vancouver Sun.

A third-party review found that the dam's design "did not take into account the complexity of the sub-glacial and pre-glacial geological environment associated with the Permiter Embankment foundation".

"The omissions associated with site characterization may be likened to creating a loaded gun," the panel concluded.

The panel also stated that additional inspections would not have revealed this fundamental flaw.