As the huge leak of documents from a Panamanian law firm turned the heat on current and former leaders of state across the globe, the chief executive of a private energy firm in India found an interesting way to introduce himself and his colleagues. After exchanging pleasantries with his guests on Tuesday, he said, "And of course, none of our names features in the Panama papers." The documents leaked from Mossack Fonseca, a law firm that specialises in setting up offshore companies in tax havens, reveal how the rich and powerful use tax havens to hide their wealth.