The US attorney’s office in Boston has expanded a probe into Sanofi-Aventis’ marketing practices, the French company revealed yesterday in its annual report.

The firm says that the so-called “private label” investigation will now include allegations that Sanofi’s Aventis Pharmaceuticals unit made payments to influence sales of the its pharmaceuticals in order to obtain or keep drug business and to evade Medicaid best price reporting requirements.

The firm has received a governmental subpoena relating to the expanded probe, which asks for documents relating to marketing interactions with, and payment to, managed care customers, formulary placement, sales and marketing of specific products to those managed case customers, as well as contracts with wholesalers and distributors and payments to non-Aventis employees.