Lima 2019 silver medallist Andressa Oliveira de Morais has been provisionally suspended following a positive drugs test, the Athletics Integrity Unit (AIU) has announced.
The Brazilian discus thrower earned a podium finish in Peru's capital city last month.
Her South American Games record throw of 65.98 metres had put the Brazilian on course to claim the gold medal.
But it was ultimately beaten by the Games record 66.58m, achieved by Cuba's Yaime Perez in the final round of competition.
The Brazilian settled for the silver medal, with team mate Fernanda Martins claiming the bronze medal on 62.23.
Cuba;s Denia Caballero finished fourth at the Games with a throw of 60.46m, but potentially could rise to third place should de Morais be stripped of her medal.
The AIU has announced the Brazilian was charged due to the presence of the prohibited substance SARM S22, an anabolic agent.
The case is currently subject to Panam Sports proceedings.
De Morais, who lies sixth in the world rankings, could be ruled out of this month's World Athletics Championships in Doha.
The South American champion is the third athlete to have been implicated in a doping offence at the Games in Lima.
Puerto Rico were stripped of their men's doubles bowling title last month after Jean Perez Faure failed a drugs test.
Dominican Republic baseball player Audrey Joel Perez was also sanctioned during the Games for testing positive for the banned anabolic steroid oxandrolone.
Dominican Republic did not lose their fifth-place finishing position, with two positive tests required for a team to be disqualified from the competition.
At the time of Perez's failed test, Panam Sports said a total of 1,197 anti-doping controls had been carried out to date, with 670 taken in competition and 527 out of competition.
This is claimed to be the one of the largest amounts of samples taken in the history of the Games.
Earlier in the Games, Peruvian swimmer Mauricio Fiol confirmed he had been ruled out of competition after being informed of a positive test by the International Swimming Federation.
It was the second consecutive Pan American Games he had been embroiled in a doping case.
Fiol was stripped of the silver medal he won in the 200 metres butterfly at Toronto 2015 after testing positive for the banned steroid stanozolol.
This led to the Peruvian being been banned for four years, which ran from July 12, 2015 and officially ended on July 11, 2019.
Stanozolol was also the substance the Peruvian tested positive before Lima 2019.
Chilean equestrian athlete Mauricio González was confirmed to have been left out of the country's delegation before the Games.
The Chilean Olympic Committee announced his positive test for marijuana on July 26.
Chile had already been forced to remove cyclists Constanza Victoria Paredas Martinez and Andreas Silva Zambrano last month from their team following positive tests.
Teenager sprinter Briana Williams of Jamaica had been due to compete at the Games, but travelled to the Peruvian city without competing.
It later emerged she had testing positive for the banned diuretic hydrochlorothiazide, leaving her participation at the World Championships in doubt.
The 17-year-old, the current world under-20 champion in the 100 and 200 metres, faces a hearing over the case.
It has been claimed the substance was contained in an over-the-counter cold-and-flu medication given to her by a close relative.
Williams' representatives have said they are seeking a "no fault" verdict, asserting that in the circumstances and there should be no sanctions levied against her,