It is to be tested on thousands of women in a trial about to start in China.

Researchers from De Montfort University in Leicester designed the bra, which they believe could be as effective, or even more effective than traditional x-ray mammograms, while being safer and cheaper.

It uses tiny electrical currents which are passed through the breast, working on the principle that the differences between healthy breast tissue and tumour tissue affect the way the current gets through.

More resistance

The denser tissue in tumours makes it harder for the electricity to get through, and sensitive measuring equipment picks this up.

So far, testing has been restricted to tissue samples in the laboratory, but the research team is confident that tests on humans will prove the value of the device.

Professor Malcolm McCormick, Head of Postgraduate Studies at De Montfort University, told BBC News Online: "It should be very much less expensive than an x-ray machine.

"I believe it has the potential to be more accurate."

He said that while mammography was most effective in post-menopausal women, where the contrast between dense tumour tissue and healthy breast tissue was more pronounced, the new technique should work well in all ages.

Three years

The link up with the company from China is believed to be the first of its kind with involving a UK university.

If trials there are successful, he said that the technology could become available here within three years.

"We see it as something that could be kept at a health centre - women could be tested quickly if they came in with concerns."