New South Wales, August 4: Australian police say an elaborate hoax in which a fake bomb was attached to a teenager was an attempt at extortion.
Madeleine Pulver, 18, was at home in Sydney when an intruder apparently entered and placed a suspected explosive device round her neck.
Police took 10 hours to remove the device, evacuating nearby streets in the wealthy suburb of Mosman.
They said the intruder left behind a note attached to the device that confirmed the motive was extortion.
The offender had had previous contact with Ms Pulver and was wearing some sort of disguise, they said.
New South Wales Police Assistant Commissioner Mark Murdoch told journalists the device turned out to be “a very, very elaborate hoax”.
“But it was made and certainly gave the appearance of a legitimate improvised explosive device. We had to treat it seriously until we could prove otherwise and that's exactly what we did and that's why it took so long.”
The device was attached “by a chain or something similar,” he told ABC radio.
The demands made on the note have not been revealed but New South Wales police Detective Superintendent Luke Moore said: “We are treating this as an attempted extortion - a very serious attempted extortion.”
BBC correspondent Nick Bryant says police were baffled by the device, saying it was very sophisticated and very confusing.
Bomb disposal experts used X-ray equipment to gain a better sense of precisely what they were dealing with, and even sought assistance from the British military.
During the operation, several streets were cordoned off in Mosman, one of Sydney's wealthiest suburbs on the city's lower north shore. Ambulances and fire crews rushed to the area.
Four people remained in the room with the schoolgirl during the operation, two bomb disposal experts and two police negotiators trying to keep her calm.
Our correspondent says that Ms Pulver, who is part of a very rich family living in a very rich part of Sydney, was apparently in remarkable spirits throughout her ordeal.
Ms Pulver was taken to hospital for checks before being released on Thursday and is now recovering with her parents.
Agence France-Presse news agency said the teenager's father, William Pulver, was a successful businessman who was chief executive of a linguistic solutions software company.
Mr Pulver said Madeleine was “in pretty good spirits”.
He told the Sydney Morning Herald: “She is a little tired and a little sore from holding this damn device in place for about 10 hours but she is now, as we are, eager to get on with her life.”
Australian Prime Minister Julia Gillard told Fairfax radio she was shocked by the case.
“When I looked at it this morning, the first thing I said was, ‘It's like a Hollywood script - the kind of thing you would see at the cinema or on TV,”' she said.
“You would never expect it to happen in real life in Australia.”