The New York Times could not identify the scientist, but a reporter claims to have seen him at one of the sites where he led Mobile Exploitation Team Alpha or MET Alpha, one of the teams of soldiers searching for illegal weapons.
"Though much work must still be done to validate the information MET Alpha has uncovered, if it proves out it will clearly be one of the major discoveries of this operation, and it may be the major discovery," 101st Airborne Division commander Maj. Gen. David Petraeus told the Times.
The troops tracked the scientist down after he passed a note to soldiers, claiming to have information about Saddam's alleged illegal weapons programs.
The scientist reportedly has documents and samples to prove his claims, the Times reports. He says he saw Iraqis bury precursors for illegal weapons months before the war, to hide and preserve them to be used later on. He also claims a biological weapons lab was burned 48 hours before the fighting began.
According to the troops, preliminary tests on the sites to which he has guided the troops indicate the presence of precursors of an illegal chemical weapon. The Times was not allowed to reveal the name of the weapon.
If proven accurate, the scientist's evidence would be a major find for the 1,000 troops that have been scouring Iraq for some proof of the weapons of mass destruction that the Bush administration said were a major reason for the war. To date, no finds have proven conclusive, and fears that Iraq would use chemical weapons on U.S. or British troops were unrealized.
An alleged link between Baghdad and al Qaeda was another rationale for the war. The scientist has provided unspecified information on that link, but the Times says it is unclear why he would know about it.
The scientist's tips could also fuel the administration's drive to squeeze Syria. While the rhetoric has cooled in recent days, Bush administration officials have slammed Syria for alleged ties to Saddam's regime and for possessing chemical weapons.
His evidence would also provide a partial explanation for why no one has yet found the massive stockpiles of chemical and biological weapons that President Bush claimed Iraq possessed — that they had been destroyed or well hidden.
It would not explain why Saddam's regime, faced with almost certain destruction and the death of its leaders, did not use the weapons — and why it developed them in the first place if not to use them.
It also does not explain why the regime would burn its lab and bury its precursors but not hide or destroy the written instructions and protective suits that U.S. troops have found at several sites.
Nor does it eliminate the possibility that the precursors are in fact residue from a legitimate civilian chemical process and that the sites yield evidence merely of bad environmental policy rather than an effort to conceal deadly weapons. One previous suspected find turned out to be agricultural material, for example.
Iraq claimed during recent inspections by United Nations teams that it had destroyed chemical weapons and buried the waste products. The regime had invited inspectors to test soil at the sites; it was not known if they were the same sites the scientist pointed out the U.S. troops.
The scientist said some of the destruction began in the mid-1990s, well before any real threat of war from the United States or others.
Last week, Saddam's special weapons and science adviser, Lt. Gen. Amer al-Saadi, surrendered to American troops still claiming that Iraq never possessed weapons of mass destruction.