Pulver was alone in her family’s mansion on August 3 when 50-year-old Paul Peters broke in and fixed a bomb-like device around her neck.

A bomb squad took 10 hours to remove the device before finding that it did not contain explosives. Pulver was uninjured in the incident.

Peters had left a note behind demanding money and an email address. New South Wales state police said surveillance footage showed Peters in several locations where it is believed he accessed the email account.

Peters fled to the US in the wake of the incident and was arrested almost two weeks after the crime at his former wife’s home in Louisville, Kentucky.

news.com.au reports that attached to the fake bomb collar was a note that read: “ACT NOW, THINK LATER or YOU will inadvertently trigger a tragically avoidable explosion.”

It apparently continued: “You will be provided with detailed remittance instructions to transfer a Defined Sum once you acknowledge and confirm receipt of this message.”

It remains unclear why Peters targeted Pulver. US federal court documents show Peters once worked for a company with links to her family, but the Pulvers have said they don’t know him.

Peters was extradited from the US to Australia in September has remained in custody ever since.

He appeared in court by video from prison when the guilty plea was entered.

His lawyer Kathy Crittenden said: “Mr Peters deeply regrets and is profoundly sorry for the impact that this incident has had on Ms Pulver and her family.”

He is charged with aggravated break and enter and committing a serious indictable offence by knowingly detaining Pulver. He faces a maximum 20 years in prison.

Picture: Getty