Police did not deny the use of the moniker, reported by Channel Ten, as they struggled increasingly yesterday to contain wild speculation about the ''very unusual'' case. "We are extraordinarily proud of Maddie" ... Bill Pulver with wife Belinda. Credit:Jacky Ghossein Investigators would not confirm whether a USB stick was embedded in the hoax bomb. But they did reveal that the note contained a threat to detonate the device - now known not to contain explosives - should Ms Pulver contact police or try to disarm it. There were no suggestions that anyone other than the intruder wearing a balaclava was involved, they said. It is thought he fled through Kardinia Road.

The year 12 student at Wenona school, who celebrated her 18th birthday at the family mansion in Burrawong Avenue almost six weeks ago, was missing her HSC trials this week after being released from hospital early yesterday morning. Madeleine Pulver. The family returned home just after 8pm yesterday. Ms Pulver's father, William, said that - despite her 10-hour ordeal seated in the kitchen chained by the neck to the device as four bomb experts worked to X-ray and identify it - she was in ''pretty good spirits''. ''She is a little tired, a little sore from holding this damned device in place for about 10 hours,'' he said as his wife, Belinda, struggled to contain her tears. Australian actor Bryan Brown in the film adaptation of Tai-Pan.

''I can tell you that we as parents are extraordinarily proud of Maddie,'' Mr Pulver said. His daughter wanted to thank the officers who helped her, including Constable Karen Lowden, who sat with her for more than three hours before investigators knew the device would not explode. The note might have been signed by a sinister fictional character ''Maddie particularly wanted to thank those few officers who spent many long hours sitting with her, showing little regard for their own personal safety in her immediate vicinity last night,'' he said. A close family friend told the Herald Ms Pulver was extremely level-headed. ''Maddie is probably the best person to be stuck in a horrible situation like this,'' she said. ''She's not emotional and she's very grounded. She's a strong girl.'' The friend said that despite the Pulvers' wealth - Mr Pulver runs an international software company - the family was discreet.

''The Pulvers are not the kind of people that flaunt their wealth,'' she said. Yesterday Wenona postponed the trial HSC exams for Ms Pulver's classmates and offered counselling to its students. It also locked its gates. Its new principal, Briony Scott, declined on police advice to speak to the media and instructed students to refrain from ''indulging in public commentary through the media or social networking sites''. But the school was abuzz with speculation. The Herald was told the family was well respected and most of the school assumed the bomb threat was an extortion attempt. The robbery and serious crime squad took over the investigation late on Wednesday night and yesterday formed a strike force.

Police interviewed neighbours and seized CCTV footage from their high-security homes, and began a systematic search of the Pulvers' three-storey property, including its computers. Loading Ms Pulver, whose mobile phone was diverting to a bubbly recorded message when the Herald tried to contact her yesterday, was expected to be interviewed by detectives last night. with Kim Arlington and Gareth Hutchens