When TWA flight 800 crashed upon takeoff from JFK Airport in 1996, killing all 230 people on board, some witnesses claimed they saw a streak of light near the plane just before it exploded. Every possible explanation, from a meteorite to a missile to an on-board bomb, was thrown into the mix during the investigation, but the cause was eventually determined–officially–to be an accidental fuel tank explosion from faulty wiring. Now, several of the people in charge of the four-year investigation are coming forward to say they were told to falsify those documents, and that the plane’s remains were looked over immediately after the crash by FBI agents.

A new documentary, named after the flight, shows interviews with six members of the investigation team who say they feel safe talking about the cover-up now because they’ve retired. They say that federal authorities undermined their findings and directed them to write their reports a certain way.

“We didn’t find any part of the airplane that indicated a mechanical failure,” one investigator says.

“There was a lack of coordination and willful denial of information,” Hank Hughes, a senior accident investigator for the National Transportation Safety Board, said. “There were 755 witnesses. At no time was information provided by the witnesses shared by the FBI.”

What they couldn’t put into the official report was that the explosion occurred as a result of an outside source, they say. And though their claims are being refuted by the former Director of Aviation Safety–Tom Haueter–the National Transportation Safety Board says it will reopen the investigation if new evidence is found to prove the first conclusion wrong.

Haueter says that there is irrefutable proof that faulty wiring caused the explosion and that there was no sign of any sort of penetration on the outside of the plane. But Jim Speer, an accident investigator at the time of the crash, said he did discover damage consistent with those that would be formed by a big blast. He requested that the right wing be tested for residue from explosives, and when the test came back positive, he said, he was “physically removed” from a room by two CIA agents.

“TWA 800” premieres on Epix next month.