News of the police demand surfaced last week after a report by The Canadian Press revealed that locomotive MMA 5017 was slated to be sold off Aug. 5 at a Maine rail yard.
The locomotive played a key role in the sequence of events that led to the July 2013 oil-train derailment, which destroyed part of the Quebec town and killed 47 people.
Police have said they stepped in to prevent the engine from being sold until after the completion of the judicial process.
The Bangor Savings Bank, a creditor for the now-bankrupt Montreal, Maine and Atlantic Railway, asked the auction house to withdraw the MMA 5017 locomotive from the lineup.
The starting bid had been set at US$10,000.
A senior executive at the bank said the counsel for the U.S. bankruptcy trustee gave them the go-ahead to sell the locomotive.
"It was indeed our understanding...that there was no legal impediment being imposed by the authorities to including 5017 in the auction," Yellow Light Breen wrote in an email.
"However...the [Sûreté du Québec] made it clear that to the contrary they needed to maintain control of the locomotive during the criminal proceedings. Both the bankruptcy trustee and the bank readily acceded to that demand."
Locomotive 'key' evidence
Canada's Transportation Safety Board said Wednesday the locomotive is being held at the Derby Rail Yard in Milo, Maine, on its behalf until it has released its final report on the Lac-Mégantic investigation.
Asked who gave the green light for the locomotive to hit the auction block, an agency spokeswoman replied in an email that "the locomotive is still being held on behalf of the TSB."
"The locomotive cannot be used or moved until the TSB officially releases it," Jacqueline Roy wrote.
Prosecutors have laid charges against train engineer Tom Harding, railway traffic controller Richard Labrie and manager of train operations Jean Demaitre.
Each former MMA employee faces 47 counts of criminal negligence causing death — one for each victim of the catastrophe.
Thomas Walsh, who represents Harding, said he was surprised to hear "one of the key pieces in the Lac-Mégantic story" had been put up for auction.
"If that were the murder weapon. . . then you would be thinking, 'Holy smokes,' " Walsh said of the locomotive.
Walsh said he wants to find out why someone gave the OK to auction off the locomotive, a machine he thinks should be locked up just in case, for example, jurors ask to see it during a trial.
He warned that it's important for authorities to show who exactly had possession of the locomotive and on which dates.
The Maine locomotive auction, meanwhile, is still scheduled to move ahead and will feature two dozen locomotives from MMA's fleet, as well as seven units identified as the property of an affiliate of its former parent company, Rail World Inc.
Auctioneer Adam Jokisch says MMA 5017 is the only unit no longer on offer.
"It was on and then it was off," Jokisch said. "I just know that the bank sent an email that said, 'Take that one out of the auction,' and we took it off."