Complex sentence: Although retired from the sport with a history of hundreds of passed drug tests, Armstrong is now subject to an investigation by the USADA lacking due process and where the USADA refuses to disclose the names of Armstrong's accusers.
Split into simpler sentences: Although retired from the sport with a history of hundreds of passed drug tests, Armstrong is now subject to an investigation by the USADA lacking due process. By way of example, the USADA has refused to disclose the names of Armstrong's accusers.