Office spokeswoman Genevieve Guilbault says authorities are approaching the final step in their work to identify fragments of human remains found in the Quebec town.
Forty-seven people were killed in Lac-Megantic last summer when a tanker train carrying volatile crude oil derailed and exploded in the middle of the community.
Officials have confirmed the identities of 39 people who died in the fiery disaster that wiped out part of the town.
Guilbault says the ongoing analyses are a last-chance effort because in some cases only a limited number of fragments are suitable for testing.
She also says the intensity of the heat from the fire in the eastern Quebec town altered samples, further complicating the identification process.
Guilbault says experts are working to confirm the identities at laboratories in Montreal, Thunder Bay, Ont., and Bosnia-Herzegovina.