Kenyan-born Bahraini Eunice Jepkirui Kirwa, who won marathon silver at the Rio Olympics in 2016, has been suspended for four years for doping, the Athletics Integrity Unit (AIU) announced on Monday.
Kirwa had been provisionally banned since May after the prohibited blood-booster EPO was detected in her blood sample. Her four-year suspension is backdated to May 7, 2019.
The 35-year-old finished second in Rio behind Kenya's Jemima Sumgong, who was banned for eight years in January for attempting to hinder an investigation into her use of EPO by supplying false documents.
Kirwa, who also won world bronze in Beijing in 2015, can appeal the ban at the Court of Arbitration for Sport.