After being caught up in a bribery scandal in Pakistan and losing a big contract in Nigeria, Cotecna, a Geneva-based company that inspects exports and imports, was keen for new business. One of the people it was counting on for help was Kojo Annan, who had been employed by the company since autumn 1995, working in Lagos. His father, Kofi, had recently been appointed secretary-general of the United Nations. The organisation was disbursing tens of millions of dollars under the oil-for-food programme, designed for Iraq to buy food and medicines with revenues from the sale of crude oil. “They were...