The 15-year-old was with four other girls at Holdfast Marina at Glenelg on Sunday evening when the incident occurred, the Guardian reported on Monday.
Lifesavers were able to rescue the others but were unable to find the Indian girl until Monday morning when her body was pulled out of the water. One girl was said to be in critical condition.
The Indian High Commission was providing support to the group, who were all involved in the sporting event. Indian consular officials are flying in from Sydney.
Pacific School Games organisers confirmed the dead girl was part of the Indian delegation but did not reveal her sport.
The week-long international event, which ended on Saturday, involved about 4,000 participants from 15 countries in primary and senior school competing in 11 sports.
"There are signs near the actual breakwater itself alerting people to the fact there are strong currents," he told ABC News on Monday.
Two boys drowned at Glenelg on New Year's Day in 2016.
The Tourism, Recreation and Sport Ninister Leon Bignell said that the South Australia government will pay for the victim's body to be taken back to India.
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