Former investigators of the 1996 TWA Flight 800 crash are urging the National Transportation Safety Board to reopen its review of the nearly 17-year-old case. In a new documentary about the crash that is scheduled to air next month, several former investigators on the case suggest that missiles brought down the New York-to-Paris plane, killing 230 people when it exploded near Long Island just minutes after it took off. This new evidence could resurrect conspiracy theories that began circulating within days of the crash. However, the NTSB concluded after four years investigating the crash that the plane's center fuel tank exploded most likely" from a short circuit, ruling out the possibility of a missile, according to the board's report. But the retired investigators claim that those findings were "falsified." "Early on in the investigation there was indication that the evidence was being tampered with," said Hank Hughes, a former senior accident investigator with NTSB, during a conference call with reporters. Hughes and others cited possible missing parts of the plane, possible explosive material and other findings that could corroborate their theory that a missile came from the north. The documentary's co-producer Tom Stalcup told CNN that the film offers "solid proof that there was an external detonation," and that a number of people have come forward confirming these claims.