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 where the USADA refuses to disclose the names of Armstrong's accusers and hides from accountability in federal court.
Split into simpler sentences: Although retired from the sport with a history of hundreds of passed drug tests, Armstrong has been the subject of an investigation by the USADA which Armstrong claims has not afforded him due process. Armstrong says the USADA refuses to disclose the names of his accusers and hides from accountability in federal court.