The Justice Department has issued grand jury subpoenas in Georgia and Michigan as part of a probe into whether Cook submitted fraudulent information on mortgage applications for properties in both states, Reuters and the Wall Street Journal reported, citing unnamed sources and U.S. officials familiar with the matter.

The allegations stem from a criminal referral issued by Federal Housing Finance Agency Director Bill Pulte last month, after Pulte claimed Cook falsified her resident status by listing two properties in Ann Arbor, Michigan, and Atlanta as her primary residence after taking mortgages in both properties.

Pulte also alleged Cook falsified bank documents and property records to acquire more favorable loan terms, and obtained mortgages that “do not meet certain lending requirements.”

Trump said he would fire Cook, whose term expires in 2038, over the claims, though Cook has challenged the move in court and accused Trump of an “unprecedented and illegal attempt” to remove her from the Fed.

Neither the Justice Department nor Abbe Lowell, Cook’s attorney, immediately responded to requests for comment.