OTTAWA — Quebec police have concluded their investigation into last July’s oil-by-rail disaster in the Quebec town of Lac-Megantic, in which 47 people were killed, and have turned the file over to the public prosecutor’s office, a police spokesman said Monday.

“The investigators of the Surete du Quebec [police] have sent the investigation report to the director of criminal and penal prosecutions,” spokesman Claude Denis said.

Neither he nor the prosecutor’s office would give details on what was in the report, or say whether, or when, criminal charges might be laid.

News agency QMI reported over the weekend that an unidentified police source said police were confident prosecutors would lay criminal negligence charges.

The disaster occurred after a single engineer parked his train for the night on a main line uphill from the small town of Lac-Megantic. The train of oil tankers started rolling and eventually derailed, exploding into balls of fire and flattening the center of the town.

The train was operated by Montreal, Maine and Atlantic Railway.

Contacted by Reuters, MMA Chairman Edward Burkhardt said he has been in touch with investigators “from time to time” to provide requested information, but that he did not know about any pending charges related to the crash.

“I have no information about them … I have no comment, I have nothing to comment on,” he said.

Jean-Pascal Boucher, spokesman for the prosecutor’s office, said the prosecution has been working with the police since the accident and that it is continuing to analyze the evidence.