The American co-ordinating the US-led search for weapons of mass destruction in Iraq said yesterday that "progress was being made" - but pleaded for patience.
Speaking after giving closed testimony on Capitol Hill yesterday, David Kay said that the process would take time. "We don't intend to expose the evidence until we have solid proof," he said.
Despite extensive questioning of captive Iraqi scientists and searching by its experts, the US has yet to come up with any compelling evidence that Saddam Hussein was aggressively pursuing chemical, biological or nuclear weapons programmes - let alone to find the weapons themselves.
As Mr Kay spoke, the political row over Saddam's alleged weapons deepened. Republicans said that evidence not only of programmes but of the weapons themselves would turn up, prompting Democrats to say that the existence of a programme, even if proved, was not sufficient.
Bob Graham, one of the Democrat's presidential candidates, who until this year headed the Senate select committee on intelligence, said: "If no weapons are found, the credibility of the US government abroad and at home will be significantly eroded."
Jay Rockefeller, his successor as the senior Democrat on the panel, declared that the discovery of a programme, without the weapons, was "not enough reason" to go to war.
Mr Kay, a former United Nations weapons inspector and an important adviser to the 1,500-strong Iraq Survey Group, claimed that as growing numbers of Iraqi scientists and technical workers co-operated with the occupying forces, new documents and information were coming to light, including tips about suspect sites previously unknown to the UN.
He insisted that his staff were subjecting every lead to three criteria - multiple Iraqi human sources, documentary evidence and physical evidence. This would establish "the full nature" of Saddam's programmes, he said.
He added: "Don't be surprised if there's a surprise", hinting that sceptics might soon be confounded.
In the end, all may hinge on the definition of "programme", and the time at which it was active. Yesterday, there was no sign that the evidence extended beyond that which has long been known. Saddam used chemical weapons in the 1980s and Baghdad admitted to the existence of a biological weapons programme in 1995. In addition, Iraq provided 12,000 pages of data to the UN last year, some of which covered past programmes.
The The Washington Post reported yesterday that US investigators had drawn a blank in their questioning of more than a dozen Iraqi scientists, all of whom denied that the former dictator had built up new hidden stockpiles of chemical and biological weapons or re-constituted his nuclear weapons programme since UN inspectors left the country in December 1998.
Among the scientists interrogated was Lt-Gen Amer al-Saadi, the scientist who was Iraq's chief liaison officer with the UN inspectors before the war. He has been held incommunicado at an American base in Iraq since he voluntarily surrendered on 12 April.
Shortly before he was taken into custody, he told German television that the supposed weapons of mass destruction did not exist. His wife told The Washington Post: "He is telling the truth ... They have realised there are no weapons."
But Mr Kay and John Warner, the chairman of the Senate armed services committee, maintained that the evidence would turn up. After being briefed by Mr Kay earlier in the week, President George Bush told reporters on Wednesday that he was confident "the truth will come out".
In Iraq, more American soldiers died. Two were killed in separate incidents near the capital, Baghdad.
Yesterday's attacks, which brought the total number of US victims of "hostile incidents" to 53 since Mr Bush declared an end to major combat operations on 1 May, show that the killing of Saddam's sons, Uday and Qusay, in Mosul last week have not brought the hoped-for end to the violence.
The State Department confirmed yesterday that a $30m (£18.6m) reward had been paid to the informant who told the US where Saddam's sons were hiding.Reuse content