The Court of Arbitration for Sport has dismissed an appeal by Russian boxer Misha Aloian who was stripped of his 2016 Olympic silver medal for doping.
CAS says its judging panel found that Olympic rules "affords no discretion and that disqualification of results is a necessary consequence" of a positive test.
Aloian won silver in men's flyweight at the Rio de Janeiro Games but tested positive for the banned stimulant tuaminoheptane.
The 29-year-old boxer retains the bronze he took in flyweight at the 2012 London Olympics.
It is unclear if the International Olympic Committee can reallocate his silver medal because there is no bronze medal bout in Olympic boxing.
Bronze medals were awarded in Rio to both Yoel Segundo Finol of Venezuela and Jianguan Hu of China.