A woman was spotted carrying a basket on the Manhattan Bridge hours before a dead baby emerged floating near the South Street Seaport — though she has since been all but ruled out as a suspect, police sources said Tuesday.

Two separate witnesses called 911 after it was reported that the baby was discovered off of lower Manhattan at about 4 p.m. Sunday to report seeing the basket-toting woman acting strangely on span, sources said.

Cops tracked down the woman, but she’d actually crossed 16 hours before the discovery, and the basket appears too small to have held the tragic tot, sources said.

She was also spotted on the Manhattan Bridge, believed to be too far north to match up with when and where the 8-month-old boy was found, sources added.

Investigators are, however, conducting DNA testing before making a final determination, sources said.

A bystander plucked the baby from the water, but he could not be saved.

The parents have not been found.