WITH her mother tied to the floor by a home invader, the four-year-old daughter of former NSW treasurer Michael Costa bravely picked up the phone and tried to dial triple 0.

"Mummy is having a little rest down here but mummy needs the phone," Deborah Costa told her traumatised daughter Valentina.

"We will get some nice police to come up and help us ... the phone is on the table."

A masked assailant had just fled the family's Hunter Valley home after a home invasion yesterday morning.

After threatening Mrs Costa and her children Valentina and two-year-old Mikos with a knife before tying Mrs Costa to the floor with wire, he demanded cash.

He left with bottles of wine, a purse and the family's Honda Civic. Mr Costa was not at home.

The Costas' ordeal has turned to a tale of bravery by little Valentina.

"I'm so proud of her. She was so brave," Mrs Costa said after the assault, which left her with minor injuries to her wrists.

Mrs Costa said that, when her daughter's first attempt to dial triple-0 failed, she held out the phone so her mother could hang it up with her tongue.

She tried again and got through. Police were on the scene within minutes.

The man broke into the home shortly after Mr Costa, also a former police minister, left to drive to Newcastle.

His wife was forced to the floor with a knife to her stomach before having her wrists and ankles bound with wire. Her two children, were screaming in terror.

"My first thought when he made me lie down on the floor was that he was going to stab me through the back," Mrs Costa said.

"I feared for my life but I was panicking about what was going to happen with the kids.

"They were screaming and I said: 'Please don't hurt the kids.'

"I just kept reassuring [Valentina] as it was happening and I said, 'Let's sing a song' and we started sing- ing songs.

"She was very brave."

The man, described as being of Caucasian appearance and medium build and height, was wearing a black balaclava and black tracksuit and had a goatee beard.

As of late yesterday, the man was still on the run.

Mr Costa said he wished he had been home at the time.

"The whole thing was very frightening, very terrifying, and like other people who have been in these circumstances we will have to deal with the psychological consequences," he said.

Reflecting on the nightmare, Mrs Costa said: "I feel like I need a glass of wine but he has bloody stolen it all."

Originally published as Valentina valiant in Costa home invasion