A raid by the Income Tax department on a few Bengaluru-based doctors and diagnostic centres seems to have blown the lid off a doctors-diagnostic centre commission nexus. The raid on five medical diagnostic centre chains in Bengaluru shows that doctors are paid for referring medical tests. According to a preliminary investigation, the commission varied from lab to lab, but the median range of 'cuts' or commission for doctors was found to be around 35 per cent in the case of MRI tests and 20 per cent in case of CT scan and other laboratory tests.