(Bloomberg News) Life insurers may be keeping at least $1 billion in unclaimed benefits owed to policyholders, beneficiaries or states, according to a Florida regulator.

Florida Insurance Commissioner Kevin McCarty, who made the estimate, said it was a "conservative number," in a conference with reporters during a break in a hearing today in Tallahassee. Officials from MetLife Inc., the largest U.S. life insurer, and Nationwide Mutual Insurance Co., the policyholder-owned insurer, were subpoenaed to appear at a hearing by the Florida Office of Insurance Regulation to explain how they determine when policyholders have died.

"We want to ensure that insurance companies use as much effort to find and pay benefits as they do to find and collect premiums," McCarty said during the call with reporters.

The hearing, which was attended by representatives from about 15 states, was held to help determine whether life insurers use Social Security Administration death records to stop annuity payments, without using that same data to identify life insurance policyholders who have died.

Liability for life insurance begins when the company receives proof of death, which is different than what happens in the annuity business, according to testimony by Todd Katz, executive vice president of insurance products for New York- based MetLife. If annuities continue to be paid out to deceased recipients, the insurer may have to reclaim those payments, he said.

Death List Check

MetLife began using Social Security data to stop some annuity payouts starting in the late 1980s, Katz said. The insurance company started using the death list to identify some life insurance policyholders' deaths around 2004. The insurer used the death record to conduct a sweep of most of its life insurance policies in 2007 and in 2010 decided it would check the list at least once a year. When matches are made, an investigation begins and beneficiaries are contacted, Katz said.

MetLife paid more than $11 billion to beneficiaries in 2010 and turned over $51 million to the states, according to a statement from the insurer.

Using the Social Security death list "can be valuable as an aid in preventing errors and fraud and as a safety net to identify the small fraction of deceased insureds and account holders for which the company may not receive a claim in the ordinary course," a MetLife statement said.

MetLife officials have also been subpoenaed to appear at a hearing in California on May 23. The National Association of Insurance Commissioners, the organization of state regulators, said this week it had formed a national task force, led by Florida, to help coordinate investigations into whether companies failed to pay benefits to beneficiaries of life insurance policies.