I have been to Mumbai airport only once, about a year ago. I did pay the porters, two of them in fact, and told them I was flying business class. They pushed me aside, ignored all the lines, pushed my baggage through an x-ray machine, and had me to the CX check-in desk in about ten minutes. I can't remember if they looked official or not. I do remember that CX used a non-airline lounge that was definitely below standard.