27 treated for airport fumes

Twenty-seven people were taken to hospital after being overcome by chemical fumes at Sydney airport on Wednesday, officials said.

Ambulances and police were rushed to the airport when passengers and staff were affected by the fumes in the departure area.

Police said about 40 people had complained of nausea and breathing difficulties and were assessed by ambulance officers.

"It has since been confirmed that the substance was... a chemical cleaning agent being used in the air conditioning," said airport spokesman Eric Aubert.

"There were no delays to flights because passengers were taken to their flights using an alternative route and the whole area has now been reopened," he said.

Hundreds of athletes, officials and journalists are pouring into Sydney every day ahead of Friday's opening of the Olympic Games.