Jamaican sprinter Nesta Carter's appeal against his disqualification from the Beijing 2008 Olympic Games, after he tested positive for a banned substance, has been dismissed by the Court of Arbitration for Sport (CAS).
The decision ends Jamaican hopes of regaining the gold medal they won in the 4x100 metres relay race at the Games in the Chinese capital and means Usain Bolt will remain an eight-time Olympic champion.
Carter was disqualified in January 2017 after he failed a drugs test for banned energy boosting substance methylhexaneamine following re-analysis by the International Olympic Committee (IOC) of samples stored at Beijing 2008.
It meant a Jamaican team also including Michael Frater and Asafa Powell were forced to hand back their gold medals.
Methylhexaneamine was only added by name to the World Anti-Doping Agency (WADA) banned list in 2010, although it was indirectly outlawed before then, and some past cases involving the drug have resulted in a warning rather than a ban.
The CAS ruled, however, that they could "not accept any of the arguments raised by Nesta Carter contending that the test results should be ignored or the IOC Disciplinary Panel decision should otherwise be overturned for certain alleged failures".
Trinidad and Tobago will now be officially awarded the gold medal, Japan the silver and Brazil the bronze.
"Finally, the CAS Panel noted that this case was strictly limited to the consequences related to the Beijing Games and issues linked with fault or negligence are not relevant since sanctions such as ineligibility or disqualification from other events were not at stake here," the CAS said in a statement.
Carter, who ran the first leg in Beijing, personally appeared at a seven-hour CAS hearing in Lausanne to plead his case.
His positive test resulted from the IOC's ongoing retesting of samples using up-to-date detection methods.
The 32-year-old also formed part of the gold medal winning Jamaican team at London 2012, but it is thought that retests of his sample from the event have come back negative.
He was also a member of the 4x100m team which won gold medals at the 2011, 2013 and 2015 International Association of Athletics Federations World Championships in Daegu, Moscow and Beijing respectively.
Bolt had been hailed as the winner of a historic "treble treble" after claiming a hat-trick of 100m, 200m and 4x100m relay titles at each of the Beijing 2008, London 2012 and Rio 2016 Games.
He had already handed back his relay medal from Beijing following Carter's positive.