Washington, Nov 9 (DPA) A US inquiry into BP's devastating Gulf oil spill could find no evidence that the British oil company ever put profit ahead of safety in its drilling operations, the inquiry's chief investigator said Monday.

The preliminary finding, presented at the start of a two-day hearing into the causes of the oil spill, rejects claims by some environmental groups and US lawmakers that BP may have cut safety corners in the run-up to the April 20 oil rig explosion.

"To date we have not seen a single instance where a human being made a conscious decision to favour dollars over safety," said Fred Bartlit, chief counsel for President Barack Obama's oil spill commission.

Bartlit also defended BP's own internal inquiry into the oil spill disaster, saying his investigation corroborated "about 90 percent" of BP's version of events.

While there may have been no conscious effort to cut costs, the commission said improvements in oil drilling technology had clearly come at the expense of strengthening safety and response efforts in the event that something goes wrong.

"Investments in oversight, safety and response capabilities failed to keep pace with the rapid move into deep water," Bill Reilly, a co-chair of the commission, said in an opening statement at the hearing.

"It appears in at least some quarters that business and regulatory culture exhibited ... a false sense of security," Reilly said.

The inquiry has previously found some missteps in the run-up to the April 20 explosion, which killed 11 oil rig workers and caused a well rupture that resulted in nearly five million barrels of oil spewing into the Gulf of Mexico.

Bartlit last month said the cement mix used to seal the ruptured well was found to be unstable in three out of four tests by Halliburton, a US company contracted by BP to make the cement. The results of the one successful test may have only come after the mix was pumped into the well.

A leak in the cement likely allowed gas into the oil pipe and has been labelled one of the key reasons for the explosion. It was unclear how much BP knew about the failed tests.

Obama's commission will present its full findings in December.