5 live Investigates reveals an unlicensed and unproven medicine is being illegally sold as a possible cure for cancer. A year-long investigation finds that desperate patients - some of them terminally ill - are being offered a blood product called GcMAF costing hundreds of pounds. It's being sold on the high street in Bournemouth. However, Professor Peter Johnson of Cancer Research UK said: "I have great concerns about people offering completely unproven treatments in return for money. It seems to me to be a very dubious practice.' The MHRA, the government's medicines regulator, says it is now investigating.