This morning's activity in the 12-year-old case has come as a result of work by the Homicide Squad's new cold case unit, called the Unsolved Homicide Team.

While Sydney police will not confirm the address of the house, it is believed it is the same house police searched with specialist cadaver dogs in July 2005.

Tegan Lee Lane was born at Auburn Hospital on September 12, 1996.

She disappeared two days after her birth, when she was discharged into the care of her mother, water polo star Keli Lane.

Tegan was the second of three babies Ms Lane kept secret from family and friends. The other two were legally adopted.

A coronial inquest in 2006 found Ms Lane had told a "litany of lies" about Tegan.

NSW Coroner John Abernethy said: "I am completely unable to accept the final version given by Keli Lane ... I am comfortably satisfied that Tegan Lane is, in fact, deceased."