A tragedy has unfolded as a young girl’s body has been located hours after her father was found dead and a small boat adrift in Sydney’s inner west.

Emergency services had rushed to Bayview Park on Burwood Rd at Concord after a passer-by aboard a vessel spotted a man’s body and raised the alarm on Saturday morning.

Police arrived with the help of the boater to find the man, believed to be in his 40s, in the water near Hen and Chicken Bay at Abbotsford about 11.45am.

Officers say the man had been seen in the small boat with a child before his body was discovered, sparking a huge emergency service search for the young girl.

It is understood the man and the young girl had set off from Cabarita Marina around 10am in a small rental boat.

After extensive search efforts spanning through Saturday afternoon, the young girl’s body was located.

7NEWS understands divers near Abbotsford made the tragic discovery.

Forensic officers are on the way to the scene.

“Both are yet to be formally identified; however, information provided indicates the man is in his 40s, while the girl is believed to be aged six or seven,” NSW Police said in a statement on Saturday evening.

A major search operation was launched for the young girl.A major search operation was launched for the young girl. Credit: 7NEWS The man had hired a vessel and was onboard with his daughter.The man had hired a vessel and was onboard with his daughter. Credit: 7NEWS

Police fear the young girl was thrown overboard by her father.

“Police received a call from a friend of the man to say that he had concerns for the child’s welfare and the man’s welfare,” Superintendent Christine McDonald said.

7NEWS understands the father sent text messages and called relatives saying goodbye, even phoning them while he was on the boat.

Police say neither the man or the girl could swim.

“Officers are providing support to the child’s mother, as inquiries continue,” police said in a statement.

Anyone with information has been urged to contact Burwood police or Crime Stoppers.

If you need help in a crisis, call Lifeline on 131114. For further information about depression contact beyondblue on 1300224636 or talk to your GP, local health professional or someone you trust.