Ecstasy, the illegal recreational drug, may hold the key to fighting certain cancers, Birmingham scientists have revealed.

A study at the University of Birmingham has found that the banned substance, along with other drugs such as the anti-depressant Prozac, contains cancer- busting properties.

Researchers backed by the Leukaemia Research Fund found more than half of lymphoma samples they studied responded to the growthhalting properties of psychotropic drugs. The drugs used included amphetamine derivatives such as ecstasy and weight-loss pills, and also antidepressants such as Prozac.

Professor John Gordon, from the University of Birmingham's Medical School, said: "We think that a range of psychotropic agents that are being used, or sometimes abused, for other reasons will now help us in our fight against all different types of cancer.

"We are excited that drugs like Prozac are effective in killing these types of cancer cells, as these anti-depressants are in such wide circulation and have an impressive safety record."

Co-lead scientist Dr Nick Barnes said ecstasy itself could not be used to treat cancer, but the properties within it could.

" We must stress very strongly that we couldn't use ecstasy itself as a therapeutic compound, as the dose required to treat the tumour would kill the patient," he explained.

"But perhaps by breaking down the actions of this designer drug we can extract its cancer-killing properties from more general toxic effects associated with its use."

Dr David Grant, scientific director at the Leukaemia Research Fund, welcomed the findings of the research.

He said: "About 10,000 people are diagnosed with a lymphoma in the UK each year and so the possibility that some of these patients can be treated with anti-depressants that have cancer-killing properties is truly remarkable."

Prozac is used by more than 15 million people worldwide, but has proved a controversial drug since it was licensed in the UK 14 years ago.

Concern has been raised over its side-effects, which are said to include heart failure, impotency, blindness, weight loss and leukaemia, though no compelling evidence has emerged to back the fears.

Ecstasy became popular in the early 1990s among nightclubbers who took it to stay awake.

Some evidence suggests it can damage the brain, causing long-term problems.

The research, published in the FASEB Journal, includes 17 samples where cases of acute lymphoblastic leukaemia and multiple myeloma were treated. When exposed to anti-depressants, the growth rates of nine significantly slowed down, while 11 reacted similarly to one or both of the amphetamine derivatives.

The Birmingham team has been working for five years in this area, supported by the Leukaemia Research Fund.

The latest study builds on Prof Gordon and Dr Barnes' previous findings that Prozac is effective in killing cells specifically from Burkitt's lymphoma, a common cause of children's cancer in Africa.