The oil-giant BP has pointed the finger at its contractors in a report on the worst ever oil-spill the US has seen.

Transocean and Halliburton come in for some withering criticism in the document into the oil-rig explosion and subsequent escape of crude.

The report said the operators of the Deepwater Horizon, Transocean, had missed crucial danger signs before the blast.

It also pointed out that the rig’s blow-out preventer — built by yet another contractor — was dispersing gas to the rig, and not to the sea as it should have been.

In all the report highlights eight key failures that in combination led to the explosion.

“The blame, when things go wrong, is like an air crash. There’s never one single reason. Very often it is a concatenation of errors and misunderstandings, lack of procedures and equipment failure. And I think this encapsulates the problem,” said oil industry expert Leo Drollas.

BP’s outgoing Chief Executive Tony Hayward said Halliburton had done what he called ‘a bad cement job’ on the well.

The report conceded though that one of BP’s engineers, along with Transocean, had misinterpreted a safety test that should have flagged-up the risks of a blowout.

11 men died in the explosion and nearly five-million barrels of oil escaped. The final cost to BP is expected to run into tens of millions of euros.

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