Australian collar bomber pleads guilty

Paul Peters, who was arrested and extradited from the United States in September with the help of the FBI, admitted aggravated breaking and entering and detaining the teenager for advantage.

The incident on 3 August last year created global headlines when a masked man broke into the multi-million-dollar home of 18-year-old Madeleine Pulver and fitted a fake bomb to her neck.

Police, bomb squad and other emergency services descended on the scene and Pulver endured a horrifying 10-hour ordeal with experts working into the night to remove the device, only later establishing it was an elaborate hoax.

Father-of-three Peters appeared in Sydney's Central Local Court on a video screen from a local prison and expressed no emotion when his lawyer entered the plea on his behalf, reports said.

Outside court, his lawyer Kathy Crittenden said Peters was "profoundly sorry" to the Pulver family. He will be sentenced later this month but has so far remained silent on why he targeted them.

A former executive at a collapsed financial firm, Peters reportedly had indirect links to the Pulver family but was not an acquaintance.

Court documents showed that Peters entered through an unlocked door and forced a black box around the teenager's neck while she was studying. He left the house leaving a letter which said the bomb could only be safely removed if they complied with his requests.

It added that his demands for money would be forwarded later.

Police tracked Peters down through his email account after he fled to Kentucky where his ex-wife lived.