Mark Lewis-Francis will be able to compete in future Olympics following a successful appeal to the British Olympic Association (BOA).
Lewis-Francis, part of Great Britain's gold medal-winning 4x100m relay team at the Athens Games in 2004, tested positive for cannabis last March.
He was given a public warning and stripped of the silver medal he won in the European Indoor Championships.
Lewis-Francis said he ingested the drug passively and avoided a two-year ban.
Following his failed test, Lewis-Francis was immediately rendered ineligible for selection at any future Olympic Games in accordance with BOA law.
Cannabis is listed as a "specified substance" on the World Anti-Doping Agency (WADA) Prohibited List.
But UK Athletics (UKA) was satisfied the substance had not been taken to enhance performance and the BOA accepted its contention at the appeal hearing.
Lewis-Francis anchored the Great Britain 4x100m relay team to a shock victory in Athens in 2004 and also at the European Championships in Gothenburg last Sunday.