Omarjan Azari is accused of a horrific terrorist plot and their parents are overseas but two of his sisters say they are just fine after police ripped apart their western Sydney home on Thursday.
Mr Azari, 22 allegedly conspired with one of the world's most wanted terrorists to execute a person at random on the streets of Sydney.
On Friday, the day after his arrest, one of Mr Azari's sisters told Fairfax Media that she had not spoken to her brother.
She also said the family were fine and did not want to talk about the raids in which more than two dozen police scoured their Guildford home during a counter-terrorism operation.
"We don't know anything about it; we don't care," one sister told Fairfax Media.
"Nothing happened here. Thank you very much but we have nothing to say."
When asked if they wanted to say anything to defend their brother, as their uncle Ehsan Azari had done, they declined.
"Our uncle has nothing to do with us," said one sister as she shook her head.
"Everything is fine, thank you."
A family friend arrived at the home in Bursill Street with her two children to offer support.
"I came to see them because their parents are overseas. I heard about it on the news yesterday afternoon," she said.
"They didn't want to talk to me at all about it. I offered to bring them some food but they said they were fine."
Later, the two sisters left their blond-brick home, which had been heavily guarded by Australian Federal Police and NSW Police officers on Thursday.
For 12 hours, officers searched the home, dug up patches of lawn and inspected an adjoining garage.
Mr Azari appeared briefly before Central Local Court on Thursday.
Police alleged he was planning a terrorist attack intended to "shock, horrify and terrify the community".
He was arrested during what has been dubbed as Australia's largest counter-terrorism operation ever, involving 800 police officers.
It is understood the 22-year-old moved to Sydney from Afghanistan a decade ago with his family and went to Parramatta High School.
He came to the attention of intelligence officers six months ago.
The sales assistant remains in custody charged with conspiring to plan or prepare a terrorist act with a number of people including Mohammad Ali Baryalei, believed to be the most senior member of Islamic State.
