Former water polo champion Keli Lane has been found guilty of murdering her baby.

Lane screamed "no", collapsed and fell off her seat on to the floor of the Sydney court as the verdict was read out. An ambulance was called.

Her mother also screamed "no" from the public gallery and burst into tears.

Lane, 35, had pleaded not guilty to murdering her daughter, Tegan, shortly after leaving Sydney's Auburn hospital in September 1996.

It took a week of deliberations for the NSW Supreme Court jury of six men and six women to reach a verdict following a four-month trial.

She was also convicted of three counts of making a false statement on oath in relation to documents dealing with her adopting out two other babies.

About ten minutes after the ambulance was called, Lane composed herself and sat in the dock with her lawyer.

Her barrister applied for bail, which was refused.

Justice Whealy told the court he "felt some sympathy for the accused" but did not want to give her false hope as the murder conviction she has carries a custodial sentence.

In thanking the jurors, Justice Whealy said, "I realise this must have been a difficult case for you" and said he would recommend the twelve never have to serve as jurors again.

He said to them, "I bid you farewell for the last time."

Lane was taken into custody until sentencing submissions in February.

Outside the court, John Borovnik, a social worker who first raised concerns to DOCS that Tegan was missing, spoke to media.

"It is in memory of Tegan that justice has been served," he said.

"She was a two-day-old baby who had no-one there for her."

'Surreal case'

At the end of an inquest in 2006, coroner John Abernethy described the case as surreal.

Lane did not give evidence at that inquest and she was not charged with Tegan's murder until November 2009.

She told police she gave Tegan to a man she first named as Andrew Morris, then Andrew Norris. She said he was the baby's father, whom she had a brief and secret affair with.

But the Crown claimed that was a fictitious person and Lane murdered Tegan because she did not want the responsibility of a child to interfere with her ambition to compete for Australia in the 2000 Olympics.

Tegan's body has never been found.

The missing person search for Tegan involved police writing to thousands of primary schools with female students and more than 500 girls were investigated.

During the trial, the jurors were given flow charts to help them keep track of the evidence presented about the police investigation.

Lane's barrister, Keith Chapple, argued the essence of the murder charge itself was in dispute.

He told the jury there was no proof of how, when or why Lane murdered her newborn child or even that Tegan was dead.

Mr Chapple said Lane "took the responsible course" by adopting out two other children.

Secrets and 'lies'

Senior Crown prosecutor Mark Tedeschi alleged Lane told 95 lies to cover up three secret and unwanted pregnancies so she could preserve her "golden girl" image.

But Mr Chapple told the jury "there are many things in the case that do not amount to lies at all".

He said Tegan's birth was unremarkable and Lane was not responsible for what other people did not notice.

Mr Chapple spoke of the passage of time involved in the case and said Lane was young when she gave birth to Tegan.

He said she gave some conflicting information about the birth of her children because she "didn't want everybody to know about her business".

Mr Chapple said adopting out two of her other children was stressful for Lane and an involved process.

The jury was warned by Justice Anthony Whealy that only three of the alleged 95 lies Lane had told were relevant to the issue of guilt, while the others could only be used to assess her character.

The judge said to find Lane guilty of murder the jury must be satisfied beyond reasonable doubt she killed the baby.

"Suspicion is never a substitute," Justice Whealy said.

Justice Whealy told the jurors that emotion was to play no part in their decision and warned them not to make moral judgements against the accused.

"Moral judgments, bias, condemnation of other people's behaviour and dislike of people have no place in a court of law," he said.

Justice Whealy said the fact Lane did not give evidence at her trial did not disadvantage her.

"It is the right of an accused person not to give evidence," he said.

Witnesses at the trial included Lane's ex-boyfriend, the former rugby league and union player Duncan Gillies, who said they were once very much in love but that he did not know she carried two pregnancies to term during their relationship.