The Quebec government is adding its name to a list of creditors seeking money from the insolvent railway company at the heart of the Lac-Mégantic train disaster.

The government said Monday that it is seeking $409 million from the Montreal, Maine & Atlantic Railway for expenses incurred and yet to come that stem from the tragedy.

The justice ministry said it filed a claim on June 13. In it, the government said it has already spent $126 million in public funds and suggests that future costs relating to the rebuilding of Lac-Mégantic could be in excess of $283 million.

The government warned the latter amount could change depending on how much is actually spent.

Forty-seven people were killed after a runaway train hauling tanker cars loaded with volatile crude oil broke loose and careened into the town, derailing and triggering a series of explosions in the early morning hours of July 6.

A large swath of the community's downtown was destroyed.

Three employees and the insolvent company itself have been charged criminally in the case.

Quebec Justice Minister Stéphanie Vallée said in a statement the government is exercising its right to recoup taxpayer money, but it also believes that the first people to be paid in the process should be the citizens of Lac-Mégantic themselves.

"We must act responsibly and take all legal options available to us to recover the maximum (amount)," Vallée said, adding an agreement with those responsible is the most favourable outcome.

"If those responsible for the disaster, some of (whom) have very substantial financial resources, proposed an arrangement to creditors, the government could then rely (on it) without penalizing those affected and in the interests of Quebecers who defrayed the costs through their taxes."

In the event the total funds accessible are the $25 million in insurance money available to the MM&A, the government has already promised those affected in Lac-Mégantic will be the sole beneficiaries, Vallée said.