Commonwealth Games:The Commonwealth Games Federation (CGF) has promised an immediate investigation into the water quality at the Delhi Games swimming venue following reports of swimmers falling sick.
CGF President Michael Fennell said the federation had not received a specific complaint but was awaiting reports from the teams.
British media have reported that a significant number of English athletes had been hit by "Delhi Belly" and a diarrhoea bug. Up to 40 English swimmers, including Fran Halsall and Rebecca Adlington, are among those who have been struggling.
"We must handle this immediately," Fennell told reporters. "If there is something that is unsafe, you can't swim in that water. We have to deal with it. It's a matter we have to deal with the greatest of urgency."
Fennell said measures had been taken to ensure the safety of food and water.
"We have ensured that the water quality is tested and food and all of that . . . we are concerned if athletes are not well and can't perform to their best. These are matters that are investigated with each team and they will give us a report," he added.
An English team spokeswoman said they had prepared for worse.
"We have 541 athletes and officials in Delhi and over the 28 days since the first ones arrived, 7-10 percent have suffered a mild stomach bug which has lasted for 24 hours, requiring no treatment and has not prevented any athlete from missing training or competition.
"This figure is lower than what we had planned for."