Mr. Paris also said that he "couldn't say" if the "proactive look" at the industry centered on either the life and health or property-casualty industry, or both.

The articles said that FBI investigators were also working with the National Association of Insurance Commissioners in the alleged probe of widespread problems in the industry.

Diane Koken, president of the NAIC and Pennsylvania's insurance commissioner, said in a statement that state insurance regulators, working through the NAIC, "have been tapped by the FBI to provide guidance in understanding the technical requirements for accounting and reporting of reinsurance transactions, including arrangements that limit a reinsurer's risk of loss."

Ms. Koken stated: "We understand the FBI is seeking to determine whether the accounting practices recently identified represent an industrywide concern. Several states are currently pursuing a number of investigations in this area and have been reconsidering existing financial reporting standards since last December."

Ms. Koken added that the NAIC "routinely provides technical assistance to state and federal law enforcement agencies, as well as state and federal regulators in insurance-related investigations."

"It is widely understood that investigations and examinations of insurer activity are treated as confidential," Ms. Koken noted.

Addressing the FBI's interest in the industry, Robert E. Vagley, president of the American Insurance Association, said in a statement: "Any time an individual breaks the law, they should be punished accordingly," but investigators need to be reminded that there are "hundreds of thousands of individuals who work diligently and honestly every day to serve the needs of policyholders. It would be grossly unfair to tar these hard-working individuals with a broad brush based on the isolated actions of a few bad actors.

"The business of insurance is based on good faith and trust; we and our member companies are committed to upholding those principles every day," he added.