Nine Australian athletes were fined 10,000 Brazilian reais (US $3,121) each after "tampering with their credentials" to enter a basketball arena where Australia played Serbia in the Olympics semifinal.

The athletes were charged with using false documents, Rio de Janeiro Civil Police said during a news conference Saturday.

After appearing in front of a judge in the early hours of the morning, the athletes were released with a two-year good-behavior bond and ordered to pay the fines.

The Australians' passports have been seized until they pay the fine.

Speaking to reporters on Saturday, Australian Chef de Mission Kitty Chiller said the Australian athletes were not at fault for the problem.

"(I am) very disappointed that our athletes had to go through what they did go through last night," she said. "I think it's very important to note that the athletes were definitely not at fault. We have and will continue to provide as much support and counseling to them and their parents."

She said Australia has started an internal investigation into how the accreditation was tampered with.

"It's unfortunately a practice that has been traditional not only in Australia but in other countries as well for many Olympic Games of putting a sticker on your accreditation with another venue access code on it," Chiller said.

(CNN)