Shares in Valeant lost another 15 per cent on Tuesday as bad news piled up for the Quebec-based pharmaceutical giant.

On Monday, the shares sold off more than 20 per cent after the company announced a delay in restating quarterly earnings and, after stock markets closed, the company revealed it is being investigated by the SEC.

"Valeant confirms that it has several ongoing investigations, including investigations by the U.S. Attorney's Offices for Massachusetts and the Southern District of New York, the SEC, and Congress," said Laurie Little, a Valeant spokeswoman.

She said the company confirmed that it "received a subpoena from the SEC in the fourth quarter of 2015 and, in the normal course, would have included this disclosure in its 2015 10-K. We do not have further detail to provide at this time."

The woes continued into Tuesday after Democratic presidential frontrunner Hillary Clinton released a campaign video in which she singled out the company by name for alleged predatory pricing of its drugs, saying at one point "I'm going after them."

The company was a stock market darling as recently as last summer when it briefly overtook Royal Bank to become the most valuable company in Canada.

But after hitting a high of more than $330, the shares have lost more than three quarters of their value as the company was first rocked by allegations its sales figures are fraudulent, then swept up into a probe by U.S. lawmakers focusing on exorbitant price increases for drugs.

Valeant shares were changing hands at $80.42 at share on the TSX at one point in the afternoon, their lowest level in almost three years.

Investment analysts who once loved the company's impressive growth story have quickly turned on the drugmaker, with Royal Bank slashing its price target in half and Deutsche Bank suspending its coverage of  the company until Valeant can sort out its issues.