Lane's appeal is set to argue the jury should have been instructed that manslaughter and infanticide were alternative charges to consider.

Her lawyers said on Sunday that details of the former water polo player's appeal will be lodged in the NSW Court of Criminal Appeal this week, and they have foreshadowed a bail application.

Benjamin Archbold said if it was agreed that manslaughter should have been put for the jury's consideration, a retrial of the case was inevitable, meaning bail was a real possibility.

''Ms Lane was on bail until she was convicted by the jury, and any successful appeal would almost certainly see her released from custody,'' he said yesterday. ''Notwithstanding our grounds of appeal, Ms Lane maintains her innocence. She absolutely did not kill her daughter, and will continue to fight for an acquittal.''

The finishing touches are being put on the appeal, with the experienced barrister Winston Terracini, SC, briefed to appear both on the bail application and the appeal.

The developments come after the trial's presiding judge, retired Supreme Court Justice Anthony Whealy, QC, revealed to Fairfax he did not personally believe the Crown had proved its case against Lane, and he was unconvinced of her guilt.

Lane, the trial heard, had multiple secret pregnancies in the 1990s, two ending in termination and two in adoption. Tegan was born at Auburn hospital on September 12, 1996, and within hours of her discharge two days later, Lane appeared at a friend's wedding without the infant. The child has not been seen since.

Lane was sentenced last year to maximum of 18 years in jail.

Among the points to be argued on the appeal is that the guilty verdict was unsafe, as it cannot be supported by the evidence.

In documents seen by Fairfax Media, it is submitted that the body of Tegan - if she is dead - has never been discovered, or located, meaning that the Crown cannot point to any deliberate act done by Lane to cause her death.

''It is submitted that the mens rea [guilty state of mind] element for the offence of murder is exceptionally weak,'' the appeal documents argue.

The appeal will also submit that the Crown failed to advise the judge that manslaughter and infanticide were legitimate legal alternatives to murder.

''It is submitted that in the circumstances of this case, it would have been reasonably open or viable on the evidence for the jury to return a verdict of manslaughter as opposed to murder,'' the appeal argues.

It would also be claimed that the trial ''miscarried by reason of the prejudice occasioned by the crown prosecutor''.

In one specific ground, the appeal will allege statements made by the senior crown prosecutor, Mark Tedeschi, QC, tainted the jury's view of the case.

In his opening address, Mr Tedeschi suggested Lane may have disposed of Tegan's body at the Sydney Olympic Park construction site two days after the baby's birth. He withdrew the statement the following day, but the appeal will argue that this did not ''cure'' the prejudice and the jury should have been discharged.

A spokeswoman for the Director of Public Prosecutions declined to comment.