A WOMAN accused of murdering her former lover’s wife and four-year-old grandson with garden shears lay in wait for her victim for 10 hours while the man who had ended their three-year affair was bound and gagged inside his home.

Chinese national Cai Xia Liao will appear in court accused of murdering four-year-old Alistair Kwong and his 60-year-old grandmother, Mai Mach.

The 45-year-old allegedly assaulted Brian Mach, her former lover, at his home in Albanvale in Melbourne’s west, then tied him up and gagged him in the living room before entering the four-year-old’s bedroom. The little boy was being babysat by his grandparents.

Alistair was fatally stabbed 18 times in his head and neck while he lay in bed, detectives said.

She is accused of waiting at the property for 10 hours until Alistair’s grandmother, Mai Mach, 60, got home from work, before attacking and killing her in the backyard.

Throughout those 10 hours, Mr Mach “slipped in and out of consciousness as he was assaulted by the accused,” homicide detective Senior Constable Harwood told an out-of-sessions hearing overnight.

Liao, who is in Australia on a tourist visa, will appear in the Melbourne Magistrates Court today charged with two counts of murder and one count each of intentionally causing injury and false imprisonment.

She appeared at last night’s hearing dressed in a white jumpsuit, only speaking to inform the bail justice she required blood pressure medication, and asking through a translator: “Can I say nothing?”

She had been in a relationship with Mr Mach, 61, for about three years but he recently called it off, Detective Leading Senior Constable Tony Harwood said.

He said Liao showed up at Mr Mach’s home about 6am on Tuesday — while he was babysitting his grandson Alistair and his wife was at work — and an argument erupted.

“Brian was assaulted and subdued,” Det Sen Con Harwood told an out-of-sessions court hearing on Wednesday.

“He’s been bound and gagged. The accused entered a bedroom where Alistair was in bed, while carrying a large pair of garden shears.”

Det Sen Con Harwood said Liao allegedly stabbed Alistair as he lay in bed, causing severe head and neck injuries, with a post-mortem revealing he had suffered more than 18 stab and slash wounds as well as defensive injuries.

Liao then allegedly waited for Ms Mach to arrive home from work and continued to assault Mr Mach, who was tied up in the living room.

Ms Mach drove into the rear yard of her home and was confronted by Liao as she approached the door, Det Sen Con Harwood said.

“Mai Mach was chased into the backyard by the accused and attacked with the same pair of garden shears, also suffering extreme neck and head injuries,” he said.

She suffered more than 23 stab and slash-type injuries, he said, as well as having defence wounds.

Det Sen Con Harwood said the alleged killing was witnessed by a neighbour, who called police.

Mr Mach was taken to the Royal Melbourne Hospital with minor injuries, requiring heavy sedation.

Flowers and a toy have been placed outside the Mach’s Albanvale home.

The hearing was told Alistair, described as “bubbly” by family friends, was the only child of Maidstone couple Amy Mach and Andrew Kwong.

A friend of Alastair’s parents, Diana Teoh, said he was a very bubbly four-year-old and an only child.

“They (his parents) are trying to be strong for the rest of the family but they are definitely very devastated,” she told the Herald Sun.

Homicide detective Sen-Sergeant Stuart Bailey said the boy’s parents were “inconsolable” over the death of their son.

Anyone with any information is urged to call Crime Stoppers on 1800 333 000.