New Zealand scientists have found that taking aspirin to prevent deep vein thrombosis (DVT) may not work for long-haul travellers.

According to a New Zealand Herald report, airline passengers who took aspirin before flying still developed dangerous blood clots. Dr Rodney Hughes carried out the Medical Research Institute study of 1000 people. He found that the longer you are on a plane, the greater your chances of developing the potentially fatal clots.

Dr Hughes said: "Our legs are a very, very, efficient pump. If for any reason that mechanism fails or if your legs aren't moving for a long time, the blood just sits there and congeals." He also warned that taking aspirin could give passengers a false sense of security and sleep throughout their flight, which increases the risk of clots.

British Airways announced this week that it is teaming up with the University of Birmingham in a new research project aimed at examining awareness of deep vein thrombosis amongst regular air travellers. The research study will examine 1000 frequent passengers' awareness of DVT and any precautionary measures they are taking to reduce their exposure to the condition.

Dr David Flower, one of BA's senior consultant occupational physicians, said: "Travellers' thrombosis is clearly an issue for which many air travellers have concerns. As an airline, we believe that more research and a greater understanding of the issues surrounding the condition will be of benefit to everyone."

BA advises passengers to drink lots of fluids, avoid alcohol and caffeine and walk around the aircraft at regular intervals to help prevent DVT.