An investigation is launched after the child was found by a passer-by in a nature reserve.
The body of a baby boy has been discovered in a canal, police said.
A passer-by spotted the child in a waterway in Rough Wood Country Park, Willenhall, at about 13:00 BST on Thursday, said West Midlands Police.
Officers are hunting the child’s mother, who they said may need urgent medical attention.
“We’re now investigating these very sad circumstances to understand exactly what has happened and if anyone has come to harm,” the force said.
Det Insp Wes Martin added: “This is a tragic investigation and our priority is to now find the baby boy’s mum to make sure she is ok.”
He urged anyone with information to get in touch.
The nature reserve was sealed off as investigations got under way.
The force urged the public not to speculate on the “distressing” incident, and appealed for anyone with information to come forward.
The discovery comes less than a month after a baby, thought to be only a few hours old, was found by a dog walker in an abandoned park in Birmingham.
Named George by hospital staff, he was found on 22 April at The Mounds in Kings Norton.
He is now doing well with foster carers, police said, but the search for his mother is continuing.
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