A New Zealand coroner has ruled that a 30-year-old woman died after drinking too much Coca-Cola.

Natasha Harris, 30, died from a heart attack three years ago.

Her family says in the months before her death, the mother of eight had consumed huge quantities of the soft drink - up to 10 litres a day.

Coroner David Crerar found her excessive Coca-Cola consumption was probably a substantial factor in her death.

He says Ms Harris was ingesting as much as twice the recommended daily amount of caffeine and more than 10 times the advised sugar intake.

Coca-Cola says it vehemently disagrees with the coroner's findings, adding that experts could not agree on the most likely cause of death.

The coroner wants health authorities to consider lowering the caffeine percentage limit in carbonated drinks or create more specific warning labels.