BP says one of its employees lost a laptop computer loaded with personal data for 13,000 Louisiana residents who filed compensation claims after the Gulf oil disaster.

The data included a spreadsheet of names, Social Security numbers, phone numbers and addresses, the Associated Press writes. The laptop was lost March 1, and although it was password protected, the data was not encrypted.

BP spokesman Curtis Thomas said the company has mailed out letters notifying the people about the potential security breach and offering to pay for credit monitoring. He added that there's no evidence anyone's information has been misused.

Asked why BP waited nearly a month before alerting the claimants, Thomas said, "We were doing our due diligence and investigating."