Tom Juby has told Fifth Estate that he was prevented by senior RCMP and aviation safety officials from pursuing his theory that the crash may have been caused by a criminal device.
The flight from New York to Zurich crashed into the Atlantic Ocean off Peggy's Cove on Sept. 2, 1998, killing 229 passengers and crew.
A Transportation Safety Board investigation concluded the plane was brought down by a fire in the cockpit that was caused by sparking electrical wires.
Juby, a former arson investigator who worked on the Swissair file, told the CBC that the TSB investigation was done "improperly" and that high levels of magnesium -- a key ingredient in an incendiary device -- were discovered in the cockpit area.
The Fifth Estate, which will broadcast the item Friday night, says it spoke to several other investigators and a federal scientist who support Juby's suspicions.
The CBC says the RCMP and the TSB repeatedly refused to comment about Juby's allegations.