The names, addresses and Social Security numbers of as many as 540,000 injured workers have been lost, and the state and a contracted company are trying to protect the workers from identity theft.

In New York, company and state officials said Monday that the data was on computer hardware that is missing from a secured facility of the company, Chicago-based CS Stars, an independent insurance brokerage.

Most of the workers are New Yorkers from across the state who are in two special funds of the workers' compensation system. One group is all workers who have a second injury and another is all workers who have a past injury that creates new problems, said state Workers Compensation Board spokesman John Sullivan.

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The state-owned personal computer provided to the contractor, CS Stars, "cannot be located," according to a letter the company sent to the people whose information was lost.

CS Stars had been using the computer to move the data from the state to the company's computerized claim system, according to the letter.

The FBI is investigating, said Mike Kachel, spokesman for CS Stars' New York City office. He declined to release details that he said could hamper the investigation, including when the computer went missing.

"At this time, we have no indication that any of the data stored on the missing hardware has been used inappropriately," Kachel said. "That doesn't lessen our desire to do what is right."

The company is offering the people identity theft insurance, 12 months to get free credit reports and access to fraud resolution specialists.

It was the latest report in a rash of government data on individuals being compromised, from a stolen Veterans Affairs laptop containing information on 26.5 million veterans to a hacker in the Nebraska child-support computer system who may have gotten data on 300,000 people and 9,000 employers.

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