Botox injections may help treat cancer says scientists who discovered that tiny doses of the potentially-lethal toxin can significantly boost the effects of chemotherapy.

The wrinkle-busting poison appears to speed up the destruction of tumour cells. It does this by relaxing the muscles in blood vessels that supply the tumour, increasing blood flow and oxygen supplies.

So when drugs are injected into the bloodstream, they have a better chance of reaching deep inside the tumour and stopping it reproducing.

The findings, published in the journal Clinical Cancer Research, contrast sharply with the latest innovations in cancer treatment.

Several new drugs focus on starving tumours of their blood supply, rather than increasing it.

But the Botox results suggest boosting blood flow can make chemotherapy far more effective.

The cancer breakthrough is potentially the most significant in a growing number of clinical applications for one of the most lethal poisons known to man, which has become most famous as a cosmetic therapy.