The US government on Thursday said BP had “failed” to meet its responsibilities to rid its Alaska pipelines of sludge - a necessary step to enabling high-tech corrosion tests that could prevent another massive oil leak.

“I continue to find that the presence of hazardous conditions on the specified pipelines,” said Stacey Gerard, the US Department of Transportation’s associate administrator for pipeline safety. “Without the implementation of corrective measures, [this] would result in likely serious harm to life, property or the environment.”