The reptile demonstration involved an inland taipan, which has the most toxic venom in the world.

A spokeswoman for Ambulance Victoria said the man in his 40s was flown to hospital in a serious condition after being bitten on the thumb about 3.30pm yesterday.

She said the man was likely to be transferred to Geelong hospital for treatment.

A woman who was at the annual building unions’ picnic, Kate Ellis, said the snake handler had only just told the audience he believed his snakes would not bite him when the taipan struck. 

“The audience was horrified,” Ms Ellis said. 

“We were very upset for him.”

She said the handler immediately put a pressure bandage on his thumb.

“He knew he was in trouble,” Ms Ellis said.

A first-aid officer treated the man before paramedics arrived.

The drama occurred in front of more than 300 people enjoying a variety of entertainment and warm weather at a sports oval in Trangmar Street.