The world's biggest study of the health effects of mobile phones found that the top 10 per cent of the users are up to 40 per cent more likely to develop glioma, a common type of brain cancer.
A study by The International Agency for Research on Cancer was carried out in 13 countries, including Australia, and involves more than 5000 brain cancer patients worldwide.
In the research, it was found that just 30 minutes of mobile talk time daily was enough to put a person into the top 10 per cent group.
The finding which was reported by British newspapers yesterday ahead of its official scheduled release this week - has ignited controversy among cancer experts, neurologist and other scientists.
Australian neurosurgeons Charlie Teo and Vini Khurana said last night the findings were a concern.
This (finding) does concern us, but it's also an impetus to do two things: the mobile phone industry has to supply the actual hours logged, and we need to track brain tumour incidence in Australia.
Other experts sought to reassure the public over the findings. IARC director Christopher Wild said an increased risk of brain cancer was not established from the data from Interphone.
Industry group the Australian Mobile Telecommunications Association also emphasised the study found no increased risk overall, and its conclusion was in line with the weight of scientific opinion, which has found no substantiated scientific evidence of any adverse health effects.
The study's authors said there was reasonable doubt about the credibility of some patients' estimates of their phone use, which in 10 cases amounted to 512 hours per day, an impossibility.