Scientists in Edinburgh say cancer patients could be helped by a new painkiller made from cannabis.

A study of 177 patients found an oral spray developed in the capital can reduce pain levels by 30%, even when morphine or other pain medication has proved ineffective.

Now, the team of researchers at Edinburgh University hopes the treatment could be offered alongside more traditional medicines.

Doctors say the spray activates molecules in the body which can stop nerve signals being transmitted from the site of the pain to the brain. And they believe that can cause a significant improvement in patients' quality of life.

The medicine has been developed in such a way that it does not affect the patient's mental state in the way cannabis ordinarily would. However, doctors say the study does not support the smoking of the drug.

Professor Marie Fallon, from the Edinburgh Cancer Research Centre at the University, said: “These early results are very promising and demonstrate that cannabis-based medicines may deliver effective treatment for people with severe pain.

“Prescription of these drugs can be very useful in combating debilitating pain, but it is important to understand the difference between their medical and recreational use.”