Mutual Fund Company T. Rowe Price Group (TROW) has sued Valeant Pharmaceuticals Inc. (VRX), claiming the drug company committed fraud that cost it and Valeant investors billions of dollars.(See also: Valeant Shares Plunge Amid Criminal Probe.)

In a lawsuit filed in New Jersey federal court T. Rowe Price contends Valeant operated a “fraudulent scheme” to artificially increase its financial results and protect it from competition on the part of other drug companies. According to the suit, which was first reported by the Wall Street Journal, Valeant used it’s now closed mail-order pharmacy Philidor RX Services to engage in deceptive pricing and reimbursements practices and made up accounting to artificially boost revenue and profits. Alleghany Cos., another Valeant investor, joined T. Rowe Price in the lawsuit.

T. Rowe Price, which at a time was one of the company’s largest shareholders said the practices on the part of Valeant put it at a huge risk that resulted in large losses. According to the Wall Street Journal at one point T. Rowe Price held 21.5 million shares of Valeant or a 6.4% stake. At its peak it had a value of $4.5 billion. T. Rowe Price unloaded the majority of its holding in 2016 after shares tanked. As of the end of June it owned 1.5 million shares, the paper noted.

The move on the part of mutual fund company to file a lawsuit against Valeant comes as the drug maker is reportedly the subject of a criminal investigation by federal prosecutors. The investigators are trying to determine whether the company defrauded insurers due to its relationship with Philidor RX. According to a Wall Street Journal report earlier this month, prosecutors are looking to see if insurers were deliberately misled into thinking Philidor, which filled prescription medication for Valeant dermatology drugs, was a neutral party rather than in the service of Valeant. Prosecutors are also trying to determine whether Philidor made false statements to insurers.

In response to T.Rowe Price’s lawsuit Valeant said in a statement the company is aware of the filing but has not been served yet. “This T. Rowe Price complaint repeats allegations and claims as in the pending securities putative class action brought against Valeant by TIAA-CREF. As with the original complaint, which was filed in October 2015, Valeant intends to defend itself and cannot comment further on ongoing litigation.”

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