WASHINGTON — Federal regulators responsible for oversight of drilling in the Gulf of Mexico allowed industry officials several years ago to fill in their own inspection reports in pencil — and then turned them over to the regulators, who traced over them in pen before submitting the reports to the agency, according to an inspector general’s report to be released this week. The report said that investigators "could not discern if any fraudulent alterations were present on these forms."

The report, which describes inappropriate behavior by the staff at the Minerals Management Service from 2005 to 2007, also found that inspectors had accepted meals, tickets to sporting events and gifts from at least one oil company while they were overseeing the industry.

Although there is no evidence that those events played a role in the Deepwater Horizon oil spill, the report offers further evidence of what many critics of the Minerals Management Service have described as a culture of lax oversight and cozy ties to industry.

The report includes other examples of troubling behavior discovered by investigators.

In mid-2008, a minerals agency employee conducted four inspections on drilling platforms when he was also negotiating a job with the drilling company, a cover letter to the report said.