The man from Colac, in the state's west, is believed to have died from respiratory failure after going to Colac Hospital on Friday suffering from flu-like symptoms.

He died the next evening and was diagnosed posthumously with the H1N1 virus.

Victoria's acting chief health officer Rosemary Lester said the man had a range of significant underlying medical problems.

"Once seen, he was intubated and ventilated to assist his breathing and transferred to the intensive care unit at Maroondah Hospital the same day," Dr Lester said.

"Unfortunately, the man's condition deteriorated and he died on Saturday evening."

Dr Lester said the man's death was a tragic outcome and extended condolences to his family.

Victoria has 1406 confirmed swine flu cases but the actual number is much higher as the state has stopped testing and tracking all suspected cases.

Dr Lester said the virus remained mild in the majority of cases.

"However, we know that for people with chronic medical conditions, influenza can be severe,'' she said.

Last week, a 26-year-old man from a remote Aboriginal community in Western Australia became the first person with swine flu to die in Australia.