(REUTERS) -- At least four U.S.-based law firms said they are investigating Kinross Gold Corp , after the company failed to disclose that low-grade ore had been found at its Tasiast property in West Africa.

The law firms have launched separate investigations to asses if the company could have potentially misled its investors.

Toronto-based Kinross reported a quarterly loss of $2.45 per share on Wednesday, after it recorded a $2.49 billion non-cash goodwill charge on the Tasiast project.

The law firms announced their intention to pursue class action claims against the company, between Thursday and Friday.

Kinross' Toronto-listed shares closed at C$10.87 on Friday.