The district attorney's office, led by Cy Vance, has been investigating Manafort, President Donald Trump's former campaign chairman, since 2017 in connection with loans he received from two banks, and has been pursuing other cases against Trump-related figures since around that time, according to a person familiar with the matter.
Vance's office is not the only state-level prosecutor's office to hedge against a potential pardon: the New York state attorney general's office has also been putting together a case against Manafort, and that case has remained open as recently as late last year, according to a law-enforcement official familiar with the matter.
A spokesman for Vance declined to comment to CNN.
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Manafort was convicted on eight financial-related charges in a Virginia federal court in August, then pleaded guilty to charges of conspiracy against the US witness tampering in September. He is scheduled to be sentenced in both cases next month.
Although double jeopardy laws generally prevent defendants from being prosecuted twice for the same offense, New York has a tax-related exemption, and Vance could file tax-related charges that could still be prosecuted even with Manafort's conviction in federal court on similar charges.
This story is breaking and will be updated.