A new peer-reviewed study of rats has found a link between exposure to mobile phones and cancer.

The findings could have enormous implications in the long-running debate over whether phone radiation has an impact on users' health.

The tests, conducted by the US National Toxicology Program, exposed rats to the radiofrequency radiation emitted by cellular phones and found "low incidences" of tumours in both the brain and the heart developing in the rats.

Animals not exposed to the frequencies did not develop tumours.

A report released with the study stated:

"Given the widespread global usage of mobile communications among users of all ages, even a very small increase in the incidence of disease resulting from exposure to [radio-frequency radiation] could have broad implications for public health".

Over 2,500 rodents were experimented on over a two-year period. The authors of the study say the brain gliomas and heart schwannomas detected are similar to malignancies seen in some epidemiological studies of phone use.

They say the study's findings "appear to support" the World Health Organisation's classification of cell phones as a possible carcinogen.

The effects were mostly limited to male rats, with Dr Michael Laeur of the NIH's Office of Extramural Research concluding that "there were no statistically significant differences in rates of glioma or schwannomas in females".

The study is the largest, most-indepth analysis of the potential link between mobile phones and cancers to date, costing the US government $25 million.

Speaking to the Wall Street Journal, former National Toxicology Program researcher Ron Melnick said:

"Where people were saying there's no risk, I think this ends that kind of statement".