World Anti-Doping Agency (WADA) officials suspended the accreditation of the Athens doping control laboratory for up to six months on Thursday, saying the Greek lab no longer meets global standards.
A WADA site visit revealed non-compliance in the areas of institutional support and investment for the laboratory.
Disciplinary proceedings were initiated in August by WADA's laboratory expert group and punishment imposed by an independent disciplinary committee.
The suspension, which began Tuesday, bans the lab from carrying out any anti-doping activities, including all analyses of urine and blood samples.
The lab can appeal the decision to the Court of Arbitration for Sport within 21 days of receipt of notice.