A MAN who buried his baby son's remains in his suburban backyard has been fined $5000.

Andrew William McDonald, 33, was all smiles as he left Melbourne Magistrates’ Court this morning after copping the fine over the incident, which could have seen him jailed for five years.

McDonald, who is expecting another child next month, claimed the premature baby was stillborn when he buried in the backyard of his Pakenham home on December 6, 2008.

His ex-wife, Carolyn, had delivered the baby – to be their fourth child – in the bath earlier that day, eight weeks before it was due, after experiencing back pain.

Defence counsel John Buxton told magistrate Dan Muling his client acted irrationally in “rather extraordinary” circumstances out of fear the couple, who abused alcohol, would be deemed unfit parents.

“His concern was that if the matter came to the attention of the Department of Human Services, they would risk losing their children,” Mr Buxton said.

“He knows it was a bad decision, he accepts responsibility and he is remorseful that happened.”

Police were made aware of the incident after Ms McDonald reported it in September 2010, the same year the couple split.

Mr Buxton asked the magistrate to keep McDonald, who pleaded guilty to the unlawful burial, out of jail because he had turned his life around.

He said McDonald worked as a qualified builder, had been in a relationship for three years and was abstinent from alcohol.

He was convicted and fined $5000.

Mr Muling said the offence, which originated from the coronial system because it prevented coroners from conducting their duties, was serious and a message needed to be sent to the community.

“Ultimately the cause of death has never been able to be established – I don’t go beyond that,” he said.

The rarely seen indictable offence under the state Cemeteries and Crematoria Act 2003 carries a maximum penalty of five years' imprisonment and a fine of $84,500.

The same charge against his former partner, 32-year-old Carolyn Diane McDonald, was withdrawn by the prosecution.

The former couple were charged on summons with the unlawful interment, or burial, on January 12, more than four years after the incident.

The death of Tyler McDonald was reported to the Coroner's Court in September 2010.

In February 2011, coroner John Olle said an inquest would not be held because he was "not satisfied that the foetus was viable at the time of delivery".

He made a determination that he did not have the jurisdiction to investigate further and the case was closed.

