The 2005 blast at BP's Texas City refinery killed 15 people

The Chemical Safety Board (CSB) found a catalogue of internal BP reports highlighting maintenance backlogs and poor infrastructure at the site.

The blast killed 15 workers and injured 180, the worst US industrial accident in more than a decade.

BP has agreed it was preventable and has allocated $1.6bn in compensation.

On Tuesday, CSB Chairwoman Carolyn Merritt blamed the explosion, "aging infrastructure, overzealous cost-cutting, inadequate design and risk blindness."

Her comments came after the publication of the reports initital findings which showed "that BP's global management was aware of problems with maintenance, spending and infrastructure well before March 2005".

"BP implemented a 25% cut on fixed costs from 1998 to 2000 that adversely impacted maintenance expenditures and infrastructure at the refinery," Ms Merritt added.

"Every successful corporation must contain its costs. But at an ageing facility like Texas City, it is not responsible to cut budgets related to safety and maintenance without thoroughly examining the impact on the risk of a catastrophic accident," she added.

Maintenance spending

Since the Texas City blast, a series of other problems have left BP facing intense scrutiny from US authorities.

The firm had to close part of its Prudhoe Bay oil field in Alaska earlier this year, after leaks were discovered in one of its pipes.

BP has also been hit by an oil leak scandal in Alaska

In early September, lawmakers at a congressional hearing said BP's neglect of pipelines in Alaska was "unacceptable".

The company is also being investigated over the alleged manipulation of crude oil and petrol prices.

Responding to the CSB report, BP said its own investigation's findings were "generally consistent with those of the CSB".

But spokesman Ronnie Chapman added: "The BP Texas City fatal investigation team did not identify previous budget decisions or lack of expenditure as a critical factor, or immediate cause of the accident."

He said that maintenance spending at Texas City had increased 40% over the previous five years and was higher than the industry average per barrel of throughput.

The CSB is due to give a briefing on its investigations on Tuesday, before unveiling its full report next March.