FILE PHOTO: The U.S. Department of Justice building is seen in Washington, U.S., February 1, 2018. REUTERS/Jim Bourg

(Reuters) - Regenerative medicine maker MiMedx Group Inc MDXG.O is under federal investigation related to two business practices, Bloomberg reported on Monday, citing people familiar with the matter.

The company’s shares fell as much as 22.7 percent to a more than three-and-a-half year low of $6.05.

The U.S. Justice Department is probing whether MiMedx overcharged the government for its tissue repair products, as well as into the company’s distribution practices, the Bloomberg report said.

The company did not immediately respond to Reuters’ queries.

Last week, the company said independent advisers were looking into certain sales and distribution practices at the company, and postponed its fourth-quarter financial results.

Up to Friday’s close, the company’s shares had fallen nearly 40 percent this year.