Nexen Energy has been ordered to suspend operations on 95 pipelines at its Long Lake oilsands operation in northern Alberta, where five million litres of bitumen, sand and oil leaked last month.

The order, issued Friday by the Alberta Energy Regulator, immediately suspends 15 pipeline licences.

AER took the action after receiving information from Nexen on Tuesday in the course of its investigation into the massive pipeline break at Long Lake in July.

The 95 pipelines covered under these licences cannot be restarted until Nexen can provide documentation proving they are being operated safely.

"Protection of public safety and the environment are the AER's top priority," AER president and CEO Jim Ellis said in a news release.

"Given that this company has already had a pipeline failure at this site, the AER will not lift this suspension until Nexen can demonstrate that they can be operated safely and within all regulatory requirements. We will accept no less than concrete evidence."

A spokeswoman with Nexen had just become aware of the AER order when she was contacted by CBC News on Friday evening and could offer no immediate comment.

AER spokesman Bob Curran wouldn't speak specifically about the problems that forced the suspension, but said the company could be found deficient on a number of issues.

"It could be maintenance, it could be monitoring, it could be inspections," he said.

The pipelines shut down under the order carry natural gas, crude oil, salt water, fresh water and emulsion.

The pipeline break was discovered July 15 by a contractor walking along the line after its detection system failed.

The pipeline is a double-walled, high-pressure line installed in 2014.