Brazilian champions Sao Paulo were forced to flee their dressing-room at halftime after it filled with an unidentified spray during their match away to Palmeiras on Sunday.

Sao Paulo coach Muricy Ramalho, who gave his halftime team talk on the pitch, said he and several members of the delegation had come close to vomiting.

'It was impossible to breath, it was extremly irritating for the nostrils and eyes,' team doctor Jose Sanchez told reporters.

Sao Paulo also complained they were unable to take showers after the game.

A police official said the spray, which had not been identified, was a matter for the two clubs and the federation.