Husband of slain Sydney woman refused bail

The incarcerated husband of alleged Sydney murder victim Dayna Isaac has been refused bail after a judge ruled her death did not amount to "special or exceptional" circumstances.

Mikkel Isaac, 31, is on remand at Kempsey Correctional Centre awaiting sentence, after last year pleading guilty to charges of commercial drug supply, directing a criminal group, supplying a firearm and supply of cannabis.

On Friday, Isaac applied for bail at Penrith Local Court where solicitor Osman Samin submitted his "distraught" client needed freedom to attend his wife's funeral, make arrangements for the care of his children and get grief counselling.

The lawyer, arguing special or exceptional circumstances, also submitted that no "unacceptable risk" existed, if Isaac were at liberty.

"Having your wife murdered while (you're) in custody ... that's a very, very difficult circumstance," Mr Samin told the court.

Mr Samin conceded a brief marital separation between the pair but said it was not conclusive, improvements had been made and constant contact had existed.

Isaac spoke to his wife the night before her death about "moving forward", the lawyer submitted, describing his client as inconsolable and the circumstances "completely devastating".

He said attending Ms Isaac's funeral - likely to be in Sydney - via audio-visual link, would be an "extremely poor substitute" for being there in person.

Crown prosecutor Lisa Graham opposed the application, arguing the tragic circumstances of Ms Isaac's death were "not unique in this jurisdiction".

It was important to distinguish the exceptional, horrific circumstances of Ms Isaac's death, from the bail application itself, Ms Graham said.

"It's a high bar he's facing," she said.

With the alleged murder occurring on Monday, she conceded the family was in a "terrible state of grief", but noted the possibility of Isaac re-offending if granted bail given "he was involved with a lot of his family in committing offences".

She told the court the family had offered a $500,000 surety to secure his release.

In refusing bail, magistrate Stephen Corry said the matters raised on Isaac's side revolved around his wife's tragic death in the last few days, but did not meet the relevant threshold.

The judge ruled that while there was an element of immediacy, people at times suffered losses when in custody.

He referred to Isaac's children being cared for by Ms Isaac's parents and mentioned that attending a funeral via AVL had been common during the COVID-19 pandemic.

Isaac, who appeared in court via AVL, showed little emotion during the hearing.

The body of Ms Isaac, 28, was found in a Penrith unit on Monday. Her partner Paul Jason Sultana, 32, has been charged with her murder in unrelated legal proceedings.