Chicago-based commercial insurer CNA Financial Corp. has become the latest insurance company operating in the US to receive a subpoena from David Kelley, the US Attorney for the Southern District of New York, regarding reinsurance practises.

With the new request issued to CNA, Kelley has now contacted at least ten companies to provide documents relating to the practice.

According to a report on Insurancenewsnet.com, CNA has come to the attention of the authorities after restating certain financial results. CNA said that it has been asked to produce documents relating to the restated results and regarding its association with reinsurance provider Accord Re.

CNA’s subpoena comes during a busy period of activity from US authorities, which has seen MetLife, XL Capital, RenaissanceRe Holdings, Assurant, PartnerRe, Platinum Underwriters and Bristol West all issued with requests for information regarding reinsurance activities.

In addition to David Kelley a number of other US officials, including Eliot Spitzer, have been probing US operating insurance companies over suspicions that reinsurance is being inappropriately used to distort company accounts.