New York (CNN) Federal prosecutors investigating President Donald Trump's former personal attorney Michael Cohen have subpoenaed his former accountant and are examining whether financial institutions improperly granted loans to Cohen, according to sources familiar with the matter.

The accountant, Jeffrey Getzel, earlier this year received a subpoena from federal prosecutors to testify in front of the grand jury convened in the Cohen case, according to one of the people familiar with the matter. The subpoena was delivered prior to the early April searches by FBI agents of Cohen's home, office and hotel room, this person said.

Getzel performed work, including the preparation of financial statements, for Cohen as part of his taxi medallion business, which prosecutors have been scrutinizing as part of their months-long criminal investigation.

Prosecutors at the US Attorney's Office for the Southern District of New York are also examining the banks that made loans to Cohen and studying whether those banks performed the appropriate vetting of Cohen's loan applications, another person familiar with the matter said. In particular, prosecutors have questioned whether there were individuals within the banks that helped Cohen get loans in instances in which he may not have been qualified to receive them, this person said.

Prosecutors have been scrutinizing a variety of documents submitted by Cohen to various institutions, including those to the Internal Revenue Service and those to Sterling National Bank, another person familiar with the matter said. In 2014, Sterling provided several loans of unspecified value to Cohen and his wife, and the two put up taxi medallions as collateral, according to public filings

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