Police have launched a desperate search for a mum who is believed to have given birth on the banks of a river in Sydney.

Emergency services were called to the banks of the Crooks River, near Wardell Road, Earlwood yesterday afternoon, after a placenta and umbilical cord were discovered.

Police say they hold grave concerns for the baby and its mother, and are urging her to go to the nearest hospital for urgent care.

Burwood Police Area Commander Detective Chief Superintendent Christine McDonald said the placenta had been sent for forensic testing with the hope of being to identify the mother.

“Child birth for many people can be a traumatic time,” she said. “I am deeply concerned for the safety and mental health of the mother and also for the safety of her baby.

“I ask she comes forward to health services, to police or anyone who can offer support. I need to know she is safe.

“There is no judgement, they need to know that we are concerned for them and that we are wanting to know they are safe. Childbirth requires a lot of health concerns.”

Detectives have established a crime scene.

Officers are appealing for anyone who lives in or was in the areas of Wardell Road and Lang Road, Earlwood, and Tennent Parade, Hurlstone Park and Ewen Park, Hurlstone Park yesterday afternoon, and may have seen a woman in distress to contact Burwood Police or Crime Stoppers.

As inquiries continue police are urging anyone with CCTV vision or information about the incident to contact Burwood Police or Crime Stoppers on 1800 333 000.

(Featured image via Google Street View)