A football team in Peru who were battling for promotion are demanding an investigation, alleging their drinks were spiked by rivals.
Tests have revealed traces of a sedative in the blood of four Hijos de Acosvinchos players.
They collapsed during the match against Sport Ancash, who deny the allegation.
Sport Ancash won the match 3-0 and clinched the promotion spot.
Hijos de Acosvinchos, who are based in the capital, Lima, want an inquiry to take place before the result is confirmed.
Team coach Americo Ibanez said: "We want the authorities to investigate this and prove where the substance came from."
He says his players were handed drinks by Sport Ancash staff during a break in Sunday's crucial match.
One of the four who collapsed, Luis Coello, said the drink had an unusual, herbal taste and made him feel unwell.
"I felt tired and heavy. At first I felt faint and then found myself in hospital," he said.
Three other Hijos de Acosvinchos players - Andy Salinas, Juan Luna and Martin Reategui - were also affected.
However, Sport Ancash's chairman, Pepe Mallqui, denied the accusations. He blamed the sickness on a meal the Hijos de Acosvinchos players had eaten before the match.
"The players had lunch very late, at around 2pm. They ate chicken with spices and minutes later had indigestion tablets.
"This and the physical effort and the dehydration must have caused these young men to faint," he said.
He said that before the match an official had said that several Hijos de Acosvinchos players had complained of stomach problems and feeling faint.
TV pictures showed the Hijos de Acosvinchos players confronting the Sport Ancash team, who play in the city of Huaraz, after the four men fainted.
Despite the events officials allowed the match to continue with Sport Ancash snatching the promotion spot.
Hijos de Acosvinchos only had to draw the match to win promotion.