Jaafar Zia told a seminar in Beirut on Tuesday no one at the world body discounted the claim Baghdad was developing nuclear weapons as outright "lies".
Considered the father of the Iraqi nuclear programme, Zia said the inspectors had been "totally convinced" Iraq did not possess nuclear bombs before the US-led invasion, nearly a year ago.
But all officials stopped short of criticising London's and Washington's claims as a "web of lies".
According to Zia, the head of the UN's International Atomic Energy Agency, Muhammad al-Baradai "contented himself with saying that the documents were not reliable, without saying that they had been falsified."
The nuclear scientist's demand for an investigation came during his first public comments since the fall of Saddam Hussein's government in April 2003.
In a study he handed to participants, Zia accused the United States and Britain of making "false allegations" over Iraq's alleged nuclear weapons programme.
He referred in particular to false accusations such as the Iraqi attempt to buy uranium from Niger, as well as aluminium tubes which would have been used for to enrich uranium.
Despite recent revelations, Hans
Blix was silent when it mattered
Zia said Iraq had completed its nuclear disarmament in 1991, after the Gulf War, and that there had not been "a single scientific or technological possibility to restart that activity. Truth was as plain as day."
Scared of telling truth?
But as war loomed in March 2003, al-Baradai and Hans Blix, the chief UN weapons inspector, asked for three more months to carry out inspections in Iraq.
The scientist added the two officials avoided making a "clear and courageous" report that there were no nuclear weapons in Iraq – and he wanted to know why.
The United States and Britain invaded Iraq on 20 March, accusing it of harbouring biological, chemical and nuclear weapons in violation of UN resolutions - but nearly a year on, those weapons have yet to be found.
Zia was speaking at a four-day seminar in the Lebanese capital on the occupation of Iraq and its consequences for the Arab world, regionally and internationally, attended by some 150 academics specialized in Iraqi affairs.
The meeting continues until 11 March.