A New York State financial services agency is investigating several large banks to see whether they fraudulently steered homeowners into overpriced insurance policies.

The investigation centers on so-called force-placed insurance that has become increasingly common since the downturn of the housing market began and homeowners had trouble keeping up with payments on their home insurance.

JPMorgan Chase, Bank of America, Citigroup and Wells Fargo are among the major companies involved in the inquiry by the office of Benjamin M. Lawsky, the superintendent of New York State’s Department of Financial Services, according to a person briefed on the investigation who asked to remain unidentified because the matter was private.

Mr. Lawsky’s office issued 31 subpoenas or other legal notices related to the case in early October, just as the state’s insurance and banking departments were merged under his new agency. His office has already turned up instances where mortgage servicing units at large banks steered distressed homeowners into insurance policies up to 10 times as costly as the homeowners’ original plans.