The death of a Christchurch man from undiagnosed blood poisoning during the height of "swine flu hysteria" is being investigated by the Health and Disability Commissioner.

Minh Tran, 44, died on July 22, within minutes of being rushed to Christchurch Hospital's emergency department with blood poisoning caused by the skin infection cellulitis, The Press reported.

Mr Tran, father of two young girls, had been to the Christchurch flu centre in St Asaph St three days in a row before his death, but his condition went undetected.

His family doctor, David Robertson, said at the time that Mr Tran's death was preventable.

"Swine flu hysteria" meant people were not always getting appropriate care, he said.

Mr Tran's nephew, Dan Lai, said he laid a complaint with the commissioner soon after his uncle's death because the family believed somebody should be held accountable.

"All professions have to be held accountable, but doctors don't seem to be held accountable for much around here for errors that they make."

He said the family had not accepted an apology from the Canterbury Primary Pandemic Group, which ran the flu centre where Mr Tran was seen before his death.

"His English wasn't perfect, so he wasn't able to question a lot of actions that doctors took, like, 'Why am I not getting more treatment and why are you not taking me seriously?'," Mr Lai said.

Commissioner Ron Paterson said he was looking into "this tragic case", with a provisional decision due before the end of the year.