An inquiry into the BP oil spill in the Gulf of Mexico has supported many of the firm’s own findings, challenging claims that the company sacrificed safety to save money.

In April 2010 the Deepwater Horizon explosion killed 11 workers and led to the worst oil spill in US history.

The panel, which was ordered by US President Barack Obama to investigate the spill, challenged claims including ones that BP had made multiple decisions because of economic reasons, which increased the danger of a catastrophic well failure, according to the BBC.

The firm was criticised over the design of the well, which used a single pipe, known as a long string, that ran from the sea floor to the bottom of the well.

While the panel’s chief investigator Fred Bartlit agreed with 90% of BP’s conclusions about the disaster, he also observed that BP had left some important information out of its investigation into the disaster.

The commission’s 13 key points included tests done to check the cement used in the well, decisions made by BP when plugging the well and the actions of those at the company in the hours before the disaster onboard the Deepwater Horizon rig.

According to the preliminary report BP and Transocean treated negative pressure tests as a complete success, while laboratory data should have prompted a redesign of the cement slurry.

Once the crew on the rig recognised there was a problem, there were several options that might have prevented or delayed the explosion, according to the report.

The report also points out that BP incurred additional risk through certain procedures.

A final report by the panel is due by 11 January 2011.