A new type of immune cell which kills most cancers has been discovered by accident by British scientists, in a finding which could herald a major breakthrough in treatment.

Researchers at Cardiff University were analysing blood from a bank in Wales, looking for immune cells that could fight bacteria, when they found an entirely new type of T-cell.

That new immune cell carries a never-before-seen receptor which acts like a grappling hook, latching on to most human cancers, while ignoring healthy cells.

In laboratory studies, immune cells equipped with the new receptor were shown to kill lung, skin, blood, colon, breast, bone, prostate, ovarian, kidney and cervical cancer.

Professor Andrew Sewell, lead author on the study and an expert in T-cells from Cardiff University’s School of Medicine, said it was “highly unusual” to find a cell that had broad cancer-fighting therapies, and raised the prospect of a universal therapy.

“This was a serendipitous finding, nobody knew this cell existed,” Prof Sewell told The Telegraph.

“Our finding raises the prospect of a ‘one-size-fits-all’ cancer treatment, a single type of T-cell that could be capable of destroying many different types of cancers across the population. Previously nobody believed this could be possible.”