Police hold grave fears for the welfare of two brothers who were allegedly abducted by their father on the far north coast on Sunday morning.
The father was arrested by police on Monday but is refusing to say where his sons are, a police spokesman said.
Jayden and Joseph Brady, aged 14 and 11, were taken from a home in Tweed Heads at 3am on Sunday.
Their father, 38, had breached an AVO court order preventing access to the children, police said.
He was charged at Byron Bay police station with breaching an AVO but is allegedly "not assisting police with inquiries," the spokesman said.
Jayden is described as being of Caucasian appearance, between 120cm to 140cm tall, of a thin build with brown hair and brown eyes.
Joseph is also of Caucasian appearance, between 120cm and 140cm tall, with thin build and brown hair.
Anyone who sees them or believes they know their whereabouts is urged to contact Triple-0 immediately.