The pre-war "oil for food" program, which was supposed to alleviate the suffering of the Iraqi people, became yet another means for Saddam to buy the influence of important people and institutions outside Iraq. Since Saddam, through the offices of the United Nations, effectively controlled all meaningful trade in and out of Iraq, he could transfer tremendous wealth to external supporters by devaluing his oil, as it were, relative to the true cost of Iraq's lawful imports. This was well-understood before the war, and it was one of the reasons why the system for containing Iraq that prevailed since the end of the Gulf War was unsustainable over the long term.
The Iraqi daily newspaper Al-Mada
has obtained a wad of documents that describes Saddam's "oil voucher" program, and it is naming names. MEMRI has translated a big chunk of the article, and it is eye-opening. I'm sure this article won't be the end of this story.