They are looking for evidence that may point to their owners' roles in the alleged plot.

Investigators yesterday discovered a BMW sedan abandoned at a Nonthaburi temple. They suspected it may have been used in the alleged plot after finding an Internal Security Operations Command access pass on its windshield. The

pass was issued to Colonel Suraphol Supradit, one of the five suspects.

Officers said earlier they were positive a Toyota sports utility vehicle belonging to Suraphol was used to usher a pickup driven by Sgt-Major Chakhrit Janthara into the Air Force terminal compound at Don Muang airport. He was allegedly there to scout locations for an attempt on Thaksin Shinawatra's life.

Police experts yesterday examined a Nissan pickup truck belonging to Chakhrit and a Nissan sedan owned by Lieutenant Thawatchai Klinchana for forensic evidence.

Thawatchai was in charge of the Daewoo sedan intercepted by police on August 24 at the Bang Phlat intersection and later found to be loaded with explosives.

The grey BMW bore a Bangkok-registered plate, Phor Samphao Tor Tao 1860. There were no records registered with the Land Transport Department - including vehicle-registration payment stickers or insurance. It was left inside Wat Khongkha at Bang Yai district in Nonthaburi on the same day the alleged plot was foiled.

The 318i model was borrowed from the Office of the Narcotics Control Board. Police are looking for dispatch documentation and the official who processed it.