Police hope a funeral held today for a baby found dead by a Sydney gardener two years ago will prompt new information on the case.

Only a few people, including several police officers, made the trip to Rookwood Cemetery in Sydney's west this morning to farewell the girl, who they named Bridget after the patron saint for babies.

The baby's body was found in August 2010 by a gardener in a cardboard gift box near a unit block at Strathfield, not far from today's funeral service.

Investigators believe Bridget was only a day or two old at the time of her death and of a south-east Asian background.

Despite extensive investigations police have been unable to identify the baby or her mother.

Superintendent Phil Rogerson says it is important police find the mother.

"We're talking about two human beings here. The baby, of course it has died, and also the mother and the relatives of that mother, they would no doubt be under significant stress to actually place a baby in a box in a garden," he said.

"The stress has also affected the gardener and the police involved in the investigation. It's something we don't particularly come across each day and we don't want to."

Police have renewed their appeal for anyone with information to come forward.