Inderjit Singh Reyat, the only person convicted in connection with the 1985 Air India bombing that killed all 329 people aboard, will not get parole before his sentence ends next year.
It was announced by Canada's National Parole Board, which on Tuesday upheld an earlier decision to deny parole to him.
The Board decided that Reyat must remain in a British Columbia prison until his sentence is completed in February 2008.
Reyat was eligible for parole last year, but the board rejected his application, saying he tried to downplay his role in the bombing of Air India's Kanishka flight.
In 2003, Reyat was sentenced to five years' imprisonment for manslaughter after he admitted to buying bomb-making materials used to explode the plane off the coast of Ireland, The Globe and Mail reported.
During the trial, two other Indo-Canadian Sikhs -- Ripudaman Singh Malik and Ajaib Singh Bagri -- were acquitted of murder and conspiracy charges.
Air India's Flight 182 exploded while at an altitude of 31,000 feet above the Atlantic Ocean, killing 329 passengers onboard, of whom 82 were children. Until September 11, 2001 attacks in the US, the Kanishka bombing was the single deadliest terrorist attack involving aircraft.
Critics have long blamed turf battles between the Royal Canadian Mounted Police and the Canadian Security Intelligence Service for the failure to avert the bombing, and for hampering the criminal investigation that followed the attack.
Last year, Canadian Prime Minister Stephen Harper announced an inquiry, tasked with investigating if authorities underestimated the threat posed by Sikh extremists in Canada and if security agencies in this country impeded the prosecution. Former Supreme Court justice John Major was appointed head of the probe.