Canadian drugmaker Valeant Pharmaceuticals International said on Wednesday it received an investigative subpoena from the California Department of Insurance in September over its ties to pharmacies and marketing.

The request follows allegations against Valeant that it used speciality pharmacy Philidor Rx Services to force customers to pay higher prices for its drugs.

The subpoena seeks materials including documents concerning Valeant’s former relationship with Philidor, now defunct, and certain California-based pharmacies, the marketing and distribution of its products in California, the company said in a filing.

 

Valeant vrx , which owns eye care products maker Bausch & Lomb, used Philidor to overcome insurer reimbursement rejections of its medications, with Philidor resubmitting claims to insurers until they were approved, according to numerous media reports late last year. It has since severed ties with the pharmacy company.

The company said it was cooperating with the investigation.