According to new research, using your mobile just before you go to sleep can stop you getting a proper night's kip.

The study was carried out by Sweden's Karolinska Institute and Wayne State University in the US, and was funded by the Mobile Manufacturers Forum.

Its findings would suggest that radiation from mobile phone handsets can cause insomnia, headaches and confusion. Scientists adds that it may also cut how much deep sleep we get, whihc in turn interferes with the body's ability to refresh itself.

The team on the project came to the conclusion that if you need to make a make a phonecall in the evening it is much better to use a landline.

The study used 35 men and 36 women aged between 18 and 45.

Some were exposed to radiation equivalent to that received when using a mobile phone, others were placed in the same conditions, but given only "sham" exposure, explains the BBC.

In a statement, the scientists explain: "The study indicates that during laboratory exposure to 884MHz wireless signals components of sleep believed to be important for recovery from daily wear and tear are adversely affected".

Researcher Professor Bengt Arnetz said: "The study strongly suggests that mobile phone use is associated with specific changes in the areas of the brain responsible for activating and coordinating the stress system".

The team also put forward the theory that radiation may disrupt production of the hormone melatonin, which controls the body's internal rhythms.

Interestingly, around half the people in the study believed themselves to be "electrosensitive", and reported what they thought may be symptoms including headaches and impaired cognitive function from mobile phone use. But, the scientists added that the participants were unable to tell if they had actually been exposed to radiation in the test or not.

Mike Dolan, executive director of the Mobile Operators Association, said the study was inconsistent with other research.

He told the BBC: "It is really one small piece in a very large scientific jigsaw. It is a very small effect, one researcher likened it to less than the effect you would see from a cup of coffee".