Here are links to official reports on investigations into the Iraq oil-for-food programme, set up by the United Nations in 1996, and responses by some of those accused of wrong-doing.
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27 October 2005: Final Volcker report concludes that some 2,000 firms linked to the UN oil-for-food programme in Iraq were involved in bribes and surcharges to the Iraqi government.
7 September 2005: Definitive Volcker report. In a highly critical assessment, the independent commission finds instances of "illicit, unethical and corrupt" behaviour and blames UN Secretary General Kofi Annan for mismanagement.
8 August 2005: Third interim report by UN appointed commission led by ex-Federal Reserve chief Paul Volcker. Former oil-for-food programme director Benon Sevan is accused of taking nearly $150,000 in bribes. Mr Sevan says the charges against him are false.
16 May 2005: US Senate Permanent Subcommittee on Investigations releases reports accusing Russian politician Vladimir Zhirinovsky and others of accepting millions of dollars in oil allocations from Saddam Hussein.
12 May 2005: US Senate committee releases report accusing British MP George Galloway and former French minister Charles Pasqua of receiving Iraq oil allocations - charges both deny.
28 March 2005: Second interim report by UN appointed commission led by ex-Federal Reserve chief Paul Volcker, which queried UN Secretary General Kofi Annan's handling of the oil-for-food affair, but cleared him of wrongdoing over an Iraq oil deal involving his son Kojo.
3 February 2005: First interim report by the Volcker commission, which sharply criticised the oil-for-food programme's chief official, Benon Sevan.