Local civil defence chief Leoncio Calderon Castillo says searchers found the bodies of two Haitian men washed up on a beach yesterday.
Another migrant's body was found in nearby waters where the 7-metre boat capsized.
Last week, a dozen Haitian migrants who took the risky sea journey looking for a better life were rescued by the Dominican navy.
The rescued migrants told authorities the boat departed early Thursday for the US island of Puerto Rico and overturned a few kilometres from shore.