THE CHIEF investigator into the crash of TWA Flight 800 refused yesterday to confirm a report in the New York Times that a trace of explosives had been found in the wreckage of the passenger cabin.
"I'm not going to comment at all on this report," Mr Robert Francis of the National Transportation Safety Boards said.
The Times reported in yesterday's edition that traces of PETN, a chemical used in plastic explosives, had been found in pieces of the wreckage pulled from the Atlantic Ocean off Long Island.
The newspaper cited as sources three senior officials deeply involved in the investigation, who spoke on condition of anonymity.
TWA's Flight 800 from New York to Paris exploded and crashed on July 17th. All 230 passengers and crew aboard were killed.
Mr Francis said the NTSB and the FBI were still trying to determine if the explosion was caused by a bomb, a missile or mechanical failure. "We need more evidence," he said.
Chemists at the FBI crime laboratory found PETN on a piece of wreckage retrieved from the jet's passenger cabin between seat rows 17 and 27, the Times reported.
The new test result comes from a piece of wreckage that was in the exact area of the passenger cabin where investigators said the centre of the blast was. One official described the wreckage as part of a seat.
Mr Francis said on Thursday that experts who studied the 1986 explosion of the space shuttle Challenger would test debris from the TWA crash to determine whether a bomb or an accident caused the plane to explode.
He told reporters the plane appeared to have been rocked by an explosion in the centre fuel tank area. It was not clear, he added, whether that was the primary explosion that brought the plane down or a secondary blast.
The bodies of 209 victims have been recovered.
The discovery meets the FBI's previously stated standard for declaring that the plane was brought down by a criminal act, the newspaper said.
Investigators are particularly interested in finding metal fragments showing shock waves, physical damage left by a blast that indicates what type of device exploded.