CHICAGO • Laura Zeng, the United States' top-ranked rhythmic gymnast and winner of five Pan American Games golds, was handed a six-month ban on Wednesday by the United States Anti-Doping Agency (Usada).

The 19-year-old, who also represented the United States at the 2016 Rio Olympics, tested positive for the banned diuretic and masking agent acetazolamide in an out-of-competition test on Oct 18, Usada said in a statement.

She provided evidence to a Usada investigation that the prohibited substance was from an altitude sickness medication, which was prescribed to her parent and given to her in response to an illness.

Usada said she believed she was being given ibuprofen and therefore did not apply for a Therapeutic Use Exemption, which is required to authorise the use of a prohibited substance in sport.

Along with her five golds from the 2015 Pan Am Games, Zeng also dominated the Pan American Championships in September, sweeping six gold medals, including the all-around title.

She also owns the top US finishes at the World Championships in apparatus and all-around competition.

REUTERS, AGENCE FRANCE-PRESSE