People familiar with the probe into the Gulf oil spill say manslaughter and perjury are among possible charges being explored by U.S. Justice Department investigators.

The sources say the manslaughter charges may be brought against companies or managers responsible for the explosion aboard the Deepwater Horizon drilling rig that killed 11 workers.

The department is also examining congressional testimony by company executives, including former BP chief executive Tony Hayward, to determine whether their statements were truthful.

Meanwhile, BP says one of its employees lost a laptop containing personal data belonging to thousands of residents who filed claims for compensation after last year's Gulf oil spill.

The oil giant disclosed the potential data security breach on Tuesday.

But BP spokesman Curtis Thomas says the company doesn't have any evidence that claimants' personal information has been misused.

Thomas says the company mailed out letters Monday to roughly 13,000 people, notifying them that their data was in the computer.

The data belonged to individuals who filed claims with BP before the Gulf Coast Claims Facility took over the processing of claims in August.