08/11/2016 11:57 EDT | Updated 08/11/2016 12:59 EDT

Valeant, Canada's Pharma Giant, Under Criminal Investigation

U.S. attorney investigating Laval, Que.-based company.

LAVAL, Que. — Valeant Pharmaceuticals says it is co-operating with authorities after a media report said it is under investigation by the U.S. Attorney's office trying to determine whether its activities with a mail-order pharmacy were fraudulent.

The Quebec-based drugmaker says it can't comment or speculate further on the course of any ongoing investigation.

The statement from the company came after the Wall Street Journal, citing people it said were familiar with the matter, reported that the U.S. Attorney's office in Manhattan is investigating whether Valeant defrauded insurers by hiding its relationship with Philidor Rx Services.

Read more: Valeant Was Canada's Largest Company. Now It's Being Called 'The Next Enron'

Valeant Ex-CEO To Make $9 Million Even As Stock Tanks

Michael 'Mike' Pearson, former chairman and chief executive officer of Valeant Pharmaceuticals International Inc., at the Bloomberg Canada Economic Summit in Toronto, Ontario, Canada, on Thursday, May 21, 2015. Pearson left the company in May amid investigations into the company's practices. (Photo: Kevin Van Paassen/Bloomberg via Getty Images)

The Journal didn't identify its sources and said a spokeswoman for the U.S. Attorney's office declined to comment.

The relationship between Valeant Pharmaceuticals and Philidor Rx Services, a mail-order pharmacy based in Pennsylvania, became public after it was disclosed in media reports in October 2015.

At the time, Valeant CEO Michael Pearson said the company didn't publicly talk about its work with Philidor previously because it was a competitive advantage it didn't want to reveal to competitors.

Valeant later severed its relationship with Philidor, which is now defunct.