A top U.S. forensic expert and veteran of high-profile cases such as the O.J. Simpson murder trial said he discovered on Friday new clues to the mysterious shooting on Chen Shui-bian.

Within hours of arriving in Taiwan, Henry Lee said his team had re-examined the bullets and casings used in the shooting that lightly wounded Chen and had found distinct markings.

"We saw some machine marks, and these machine marks need further study," Lee told reporters before departing for the city of Tainan, where the shooting occurred.

"Naturally every machine will leave a unique mark so we are investigating further," added Lee, who arrived with his team early on Friday with boxes of high-tech equipment. He declined to give more details about the case.

Chen was shot on the eve of March 20's highly disputed election, which the "president" won by a slim 0.2 percent margin.

Many have voiced suspicion that the attack was staged to win sympathy votes and demanded a impartial probe.

Chen was gashed across the stomach and his running mate Annette Lu was wounded in the knee by two bullets fired from a homemade handgun as they campaigned in an open-top Jeep.

Lee has said the attack with a low-powered gun did not look like a professional job nor did it look like self-inflicted.

Police say they have no suspects for so far, but are seeking two men seen on security video leaving the scene within minutes of the attack, one on foot and the other on a scooter.

Lee, head of a forensics institute in the U.S. state of Connecticut, is set to interview doctors and nurses who treated the Chen in Tainan, as well as inspect the Jeep and the scene of the shooting.

Opposition Kuomintang leader Lien Chan says sympathy votes swung the outcome, pointing to opinion polls in his favour before the attack.

(China Daily/Agencies  April 10, 2004)