The 34-year-old sprinter was included in the squad for London following the conclusion of a long-running legal battle which ended when the Court of Arbitration for Sport (CAS) ruled in his favour in April.
Chambers, who has not competed in the Olympics since a fourth-place finish at the 2000 Sydney Games, was banned for two years after testing positive for drugs in 2003 as the Bay Area Laboratory Co-operative (BALCO) scandal broke.
Under a British Olympic Association (BOA) bylaw, athletes testing positive for drugs were banned for life from competing at the Olympics.
However the BOA rule was declared to be in contravention of the World Anti-Doping Agency (WADA) code by CAS, paving the way for Chambers to return.
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