The study looked at "sunburn cells", which self-destruct when exposed to UV light.

However, scientists at the Imperial Cancer Research Fund have been quick to warn that this does not mean that sunburn prevents cancer.

The study found that the suicide mechanism only worked when a certain protein was present, and may help explain why some people are more susceptible to skin cancer than others.

Exposure

Researchers from the University of Texas exposed two groups of shaved mice to UV light - the part of sunlight that causes the skin to tan and burn.

One set of mice had been bred to lack the protein that is involved in cell suicide.

In this group, the researchers found far fewer "sunburn cells" and 70% of them built up potentially cancer-causing cell mutations.

Only 5% of the mice with the protein developed such mutations.

Laurie Hill led the research, which is published in the journal Science. She said the findings showed that the cell suicide mechanism was "pivotal" in the growth of sunlight-induced cancers.

Risks explained

Dr Tony Quinn, of the Imperial Cancer Research Fund's skin tumour laboratory at St Bartholomew's Hospital, London, said: "What the research suggests is that if this pathway is disturbed it may be a way that cancer can occur.

"It could explain why some people in the population are more at risk from sunlight."

However, getting sunburnt was not the way to avoid skin cancer, he said.