(Reuters) -The U.S. Justice Department’s criminal division is digging into business practices at UnitedHealth Group’s pharmacy benefit manager, Optum Rx, Bloomberg News reported on Tuesday, citing people familiar with the matter.

Under an ongoing probe into the company’s operations, the investigators are looking into its prescription management services and how it reimburses its own doctors, the report added.

UnitedHealth is also under investigation by the U.S. DoJ over its Medicare business, a U.S. government program that covers medical costs for individuals aged 65 and older and those with disabilities.

When contacted for comments on Tuesday, the company directed Reuters to its July filing, where the conglomerate said it is complying with both criminal and civil requests from the federal agency.

The Justice Department has not accused UnitedHealth or its executives of wrongdoing and the existence of a probe does not mean that charges will be filed, the report added.

The DoJ did not immediately respond to a Reuters request for comment.

Optum Rx is one of the top three pharmacy benefit managers in the United States.

Pharmacy benefit managers negotiate drug prices and create coverage lists for health plans, mainly for employers and the government. They pay pharmacies directly for prescription drugs under their agreed terms.

They have come under fire from lawmakers as well President Donald Trump. The president has called them middlemen who drive up costs and said he plans to eliminate their role.

(Reporting by Sriparna Roy in Bengaluru; Editing by Vijay Kishore and Maju Samuel)