A computer hacker may have stolen "personal identity information" for 26,000 current and former US Agriculture Department (USDA) headquarters employees, agency officials, quoted by a Reuters report, said.
The report said the USDA announced the security breach shortly before midnight, nearly three weeks after it occurred. It then offered one year of free credit-monitoring services to the potentially affected employees.
The agency said that its computer systems were illegally accessed during the first weekend of June, according to the report.
Officials said that at first they thought the personal information was still protected, but now they were not sure whether or not the data was safe.
At risk were the names, social security numbers and photos of USDA headquarters employees and contractors, the Reuters report said.
The 26,000 names were equal to one-fourth of USDA's work force. The information was in the same database as work site information that was open to the public, the report said.