Oldest story in the world: Rio Tinto Plc, a global mining company, wanted to win some mining rights in Guinea. It needed a local representative to help it navigate Guinean politics, so it found “a French investment banker and former classmate of the Senior Government Official” in charge of the mining-rights decision, and hired him as a consultant. The consultant “had no direct work experience relating to the mining business,” but he was buddies with the guy making the decision, and that is the main thing you want.
The etiquette here is that the consultant should do a good job of advocating for Rio Tinto, making relevant arguments and providing analyses of the benefits of Rio Tinto’s plans and oh yes absolutely having a nice dinner with the government official and reminiscing about their school days. Friendly but also professional. And in return Rio Tinto should pay him a nice consulting fee. But if Rio Tinto were to hand him a sack of cash, and he were to take some of the cash out of the sack for himself and hand the rest to the government official, that would be bad! But you can see how the boundaries might be blurry. He is a consultant, Rio Tinto is not supervising him closely, and the whole point of the arrangement is that he is closer to the official than they are.
Source: Bribes – Bloomberg