Doctors in Sweden studied more than 7,000 women who had had breast implants and compared them with a group of more than 3,000 who had undergone breast reduction surgery.

They found no meaningful association between women with implants and cases of connective tissue, or immunological, disease.

In fact the women with augmented breasts were statistically slightly less likely to have encountered these diseases than the breast reduction group.

Orlof Nyren, author of the BMJ article, says evidence has concluded breast implants are safe ('0 ''16).

"Our data add to the emerging consensus that there is no important association between breast implants and connective tissue disease," said the scientists from Karolinska Institute, Stockholm.

Model Melinda Messenger has implants

The findings, published in the British Medical Journal, come as the British Government prepares to publish a report on the safety of silicone breast implants.

Silicone breast implants were developed in 1962 and in 80% of cases are used for cosmetic improvement.

Dr David Sharpe, president of the British Association of Aesthetic Plastic Surgeons, hoped the government would take note of the new findings.

"Common sense would suggest that the results of this latest study are correct," he said.

"Silicone is an inert substance that does not cause disease. Each year a diabetic will inject far more silicone into his or her body than leaks from a breast implant with absolutely no ill effects."

Writing in the British Medical Journal, three surgeons criticised the media for being too "eager to seize on any negative information about silicone implants or proponents of it, often allowing little time for an objective scientific response".

Controversy over implants

Concern over leaky implants

By 1992, between one and 2.5 million women had implants fitted in the US. Up to 150,000 women in the UK are currently estimated to have them.

But since the early 1980s doubts over the safety of silicone breast implants have stirred up fierce controversy, especially in America where they produced a welter of legal claims.

The chief concern was a possible link with connective tissue diseases, in which the immune system reacts against the body's own organs and tissues.

Rheumatoid arthritis is one such disease, but sclerosis - the hardening of organ tissue - is most commonly associated with silicone breast implants.

In 1991 an American jury found that a patient had contracted connective tissue disease from her breast implants and the manufacturer had misrepresented the safety of its product.

Soon afterwards the Food and Drug Administration requested a moratorium on the use of implants other than within trial. By 1994 manufacturers had earmarked a large fund to cover the possibility of extensive damages awards.

Yet evidence linking connective tissue disease with silicone breast implants has been almost entirely anecdotal, with only one large study in America showing a weak association.