Doping allegations are nothing new for the Nike-sponsored Oregon Project. The most recent development: The U.S Anti-Doping Agency has served Dr. Jeffrey Stuart Brown, a Texas-based endocrinologist, an official notice of rules violations for allegedly prescribing thyroid hormone to some Oregon Project runners.

The hormone Brown is accused of prescribing is usually used to treat patients with hypothyroidism, but reportedly causes weight loss and improved alertness in athletes.

Alberto Salazar, running coach for the high-octane group of long-distance runners, has long been scrutinized for his alleged prescribing of performance enhancing drugs for years. WW covered allegations against the running coach in 2015, and again last month after the release of a 269-page report from the U.S Anti-Doping Agency was released.

"Anti-doping officials depicted Salazar as a medicine chest whose door swung open for the world-class athletes on Nike's payroll. They said he provided or helped gain access to prescription-dose vitamin D; calcitonin; ferrous sulfate; Adviar; testosterone; and various thyroid medications," Matt Hart, New York Times reporter, wrote in the article last month.

This most recent report suggests that Dr. Brown may have been Salazar's supplier. In his career, Brown has made a name for himself by diagnosing runners with hypothyroidism. He is also Salazar's personal physician, and received a monthly retainer for treating Oregon Project athletes.

Though Brown and Salazar have denied all accusations made against them, this notice of rules violations could be a first step towards sanctions being issued. Both men declined comment to the New York Times.