An substance attached to the anthrax in a letter sent to the offices of Senate Majority Leader Tom Daschle indicates that the deadly poison was concocted in Iraqi laboratories, confirming a report by an Iraqi weapons expert cited in a print exclusive by NewsMax.com earlier this week.

"An urgent series of tests conducted on the letter at Ft. Detrick, Md., and elsewhere discovered the anthrax spores were treated with bentonite," ABC News reported late Friday.

"As far as is known, only one country, Iraq, has used bentonite to produce biological weapons," ABC News said.

The unique Iragi biological component helps keep anthrax particles from sticking together, thereby making the substance more easily airborne and all the more deadly. Bentonite is considered by biological weapons experts to be an Iraqi "trademark," ABC News reported.

The discovery of benonite in the Daschle letter anthrax is the first evidentiary link between the wave of anthrax attacks that has hit the U.S. in the last two weeks and Saddam Hussein.

"It means to me that Iraq becomes the prime suspect as the source of anthrax used in these letters," former U.N. weapons inspector Timothy Trevan told ABC News.

Late Monday, the one-time head of Saddam Hussein's nuclear weapons program, Dr. Khidhir Hamza, said that there was no doubt Iraq had produced the anthrax used in the current wave of bioterror attacks on the U.S.

"This is Iraq," Dr.Hamza told CNBC's "Rivera Live." "This is Iraq's work."