Two boys digging in a beach in Sydney, Australia, unearthed a dead baby.

The body was found early on Sunday at the south end of Sydney's Maroubra Beach by boys aged six and seven, who were digging about 20m from the water.

Police are attempting to establish the child's identity.

Inspector Andrew Holland said the infant's body was too decomposed to establish its age, sex, or the cause of death, and that police were concerned about the mother's well-being.

"Police are concerned about the welfare of the mother involved and hope she sought medical assistance," he told reporters.

"We're making some inquiries through births, deaths and marriages to determine where we can find the parents of this child. We're hopeful the parents will come forward."

Inspector Holland added that the sand around where the body was found is also being removed for forensic tests. He said post-mortem tests would be conducted on the body.

The two boys who found the body are currently receiving counselling.

The discovery comes days after a baby was found, alive, in a drain in Quakers Hill, Sydney, having been left for days.

A 30-year-old woman has been charged with the attempted murder of the child.

Locals expressed concern for the well being of the boys who found the body as well.

"The under-six nippers were digging in the sand and they found it," one surf lifesaver, who did not wish to be named, told Daily Mail Australia.

"It's just awful. It will have traumatised the poor the kids for life, no matter how much counselling they get.

"It hits so close to home. Especially after that baby was found in a drain last week."