Mobile phones do not present a health hazard, at least in the short term, according to the UK's largest investigation on the topic conducted by the Mobile Telecommunications and Health Research (MTHR) Programme.

The six-year research programme stated in its 2007 Report (PDF) that there is no association between short-term mobile phone use and brain cancer.

Studies on volunteers also showed no evidence that brain function was affected by mobile phone signals or the signals used by the emergency services.

The research included the largest and most robust studies of electrical hypersensitivity undertaken anywhere in the world.

The studies have found no evidence that the unpleasant symptoms experienced by sufferers are the result of exposure to signals from mobile phones or base stations.

The MTHR programme also investigated whether mobile phones might affect cells and tissue beyond simply heating them, but found no evidence to support this hypothesis.

"This is a very substantial report from a large research programme, and has been published in respected peer-reviewed scientific or medical journals," said Professor Lawrie Challis, chairman of the MTHR.

"The results are reassuring, but there is still a need for more research especially to check that no effects emerge from longer-term phone use by adults and children."

The programme's management committee said that it sees no need to support further work in this area, given the comprehensive nature of the report.

However, the committee added that the situation for longer-term exposure is less clear as studies have only included a limited number of participants who have used their phones for 10 years or more.

As a result, the committee has recommended that more long-term research is conducted in this area, a decision supported by other experts.

"It all sounds pretty reassuring and that is good. But we cannot rule out the possibility that cancer could appear in a few years," said Professor Challis, emeritus professor of physics at the University of Nottingham.

"The epidemiological evidence is not good enough and most cancers take longer than 10 years to develop."

The report has not satisfied everyone, however, including mobile mast opposition group Mast Sanity.

"There are more and more cancer clusters around mobile phone masts being reported in the UK media," said Yasmin Skelt, a spokeswoman for Mast Sanity.

"The MTHR programme should urgently investigate these clusters with a full, fine-grained and well-funded epidemiological study."