The public prosecutor's office in Paris said this week it was opening a formal judicial inquiry into alleged corruption by a French engineering firm and the American oil services giant Halliburton, which was headed until two years ago by Dick Cheney, the vice-president of the United States. The financial crimes squad in Paris believes a French oil and gas engineering firm, Technip, and particularly the Halliburton subsidiary KBR were jointly involved during the 1990s in the payment of up to $200m (£120m) of under-the-counter "commissions" in relation to a huge gas contract in Nigeria.