Clothing and wrappings in which the child were found are consistent with the descriptions of Zara Malani-Lin Abdur-Raheem, state police spokesman Sgt. Stephen Jones said.
But he said the infant is considered unidentified until DNA testing or other means can prove her identity.
Prosecutors say the infant's father, Shamsid-Din Abdur-Raheem of Galloway Township, killed her several hours after abducting her from her grandmother's apartment in East Orange. He has pleaded not guilty to murder charges filed in Middlesex County, where the bridge is located, and several related charges in Essex County, where police say the kidnapping occurred.
The 21-year-old Abdur-Raheem is being represented by the state public defender's office. Tom Rosenthal, an office spokesman, declined to comment Saturday afternoon on the discovery of a body.
The baby's mother, Venetta Benjamin, had been seeking a restraining order against Abdur-Raheem on the day the abduction occurred, he lawyer said. Jones said she has been notified of the discovery, but he declined to comment further.
Phone messages left Saturday afternoon for Benjamin and her attorney, Mitchell Liebowitz, were not immediately returned. Benjamin, a 23-year-old college student, has previously said she believed her ex-boyfriend was lying and the baby was still alive.
Authorities have said Abdur-Raheem abducted the baby from her grandmother's apartment around 4 p.m. on Feb. 16, choking and assaulting the woman and then striking her with his van as she attempted to block his escape.
Abdur-Raheem later parked his vehicle on the southbound shoulder of the highway over the Driscoll Bridge - which spans the Raritan River between Sayreville and Woodbridge - and threw or dropped the baby from the front passenger window, authorities said.
Jones said the body was found just after 8:30 a.m. Saturday by people who were walking along the southern bank of the Raritan River in Sayreville. The baby was found just east of the Route 35 bridge, which is also known as the Victory Bridge, not far from where the baby is said to have been thrown.
An autopsy will be performed at the North Regional Office in Newark, Jones said, adding that DNA samples will be processed at the state police lab as soon as possible.