Archbishop Jozef Wesolowski was recalled to Rome last year after reports that he had molested young men.
The archbishop now faces criminal charges both in the Dominican Republic and in his native Poland.
Archbishop Jude Thaddeus Okolo, who replaced Archbishop Wesolowski in the Dominican Republic, said that the Vatican is committed to learning the truth about the charges against his predecessor, while protecting any victims.
He said that Vatican officials will remain in close contact with law-enforcement officials in the Dominican Republic about the case.
Francisco Dominguez, the justice minister of the Dominican Republic, has reported that his investigation found evidence of serious criminal activity by the former nuncio and another priest.
The Vatican has promised to cooperate with Dominican prosecutors, and has indicated that Archbishop Wesolowski could be subject to a criminal trial by a Vatican tribunal.