Prosecutors also want documents related to information Valeant provided to Medicare and Medicaid.

Valeant said that it had received subpoenas from the U.S. Attorney's Offices for the District of Massachusetts and the Southern District of New York, requesting documents related to programs Valeant runs that help patients afford its medication, as well as documents on product distribution and pricing decisions.

U.S. prosecutors are probing Valeant Pharmaceuticals over how it prices and distributes drugs, the Canadian pharma giant revealed in a statement late Wednesday.

Valeant chairman and chief executive Mike Pearson said that the company believed it had operated the business in a "fully compliant manner".

"We remain committed to assisting eligible patients who need our products, and we will be working with the appropriate groups to submit the requested documents and plan to cooperate with the inquiries," he said.

The pricing of medication in the U.S. has been in the spotlight since Democratic presidential candidate Hillary Clinton lambasted Turing Pharmaceuticals in September over a 5,500 percent hike in the price of Daraprim, a drug used to treat malaria and dangerous parasitic diseases. Her promise to take on "price gouging" should she be elected sent biotechnology stocks tumbling.

Read MoreDrug prices: Which companies may be the next targets?

Valeant also revealed in its statement that it had responded to questions by Democrat Senator Claire McCaskill over the price of drugs called Nitropress and Isuprel.

The Wall Street Journal reported Wednesday that Valeant told Sen. McCaskill that it spent $544 million in 2014 to help patients cover the out-of-pockets costs levied by private insurers, and would spend $630 million in 2015.

The WSJ cited a research note from Sector & Sovereign that found Valeant's drug prices had grown at a compounded annual rate of 48 percent, making the company one of the biggest contributors to drug market inflation over the past 18 months.