( CNN ) -- An Australian businessman pleaded guilty Thursday to strapping a fake bomb around an 18-year-old girl 's neck in an attempt to extort money from her family , a court representative said . The guilty plea by Paul Douglas Peters at Sydney Central Local Court is the latest development in a case that grabbed the attention of the international news media last summer . Peters , who is in his 50s , was traced to the United States and arrested in Kentucky , more than 9,000 miles from suburban Sydney where the dramatic events took place in early August . He was extradited back to Australia in September . The authorities say Peters attempted to extort money from Madeleine Pulver 's family in the suburb of Mosman by fastening a black box around her neck . In a note , he said the box contained `` powerful new technology plastic explosives '' that would go off if Pulver did not follow his instructions , according to a complaint for provisional arrest filed in U.S. District Court in Louisville , Kentucky . Those instructions included orders to write to an e-mail address and wait for details on handing over an unspecified amount of money . Pulver spent nearly 10 agonizing hours in her bedroom as the authorities tested the box to make sure it would not explode before removing it from her neck . At the same time , the authorities say , Peters was stopping off in his four-wheel-drive Range Rover at a library and video store to check the e-mail account he had given Pulver and whiling away at least part of the time at a liquor store browsing for wine . Peters , who worked in investment banking and law , on Thursday pleaded guilty to one count of aggravated breaking and entering and committing a serious indictable offense , a representative of the New South Wales Courts Service Center said . He will be sentenced later this month . Investigators in Australia and the United States say they linked Peters to the e-mail address using video surveillance and access logs , and found credit card records showing that he had purchased a thumb drive , lanyard and baseball bat identical to those used in the extortion attempt , according to the complaint . The document says he sauntered into Pulver 's room on August 3 , wearing a business shirt , slacks and a blue , yellow and white mask that covered everything but his mouth and a pair of `` saggy and wrinkly '' eyes . He was carrying a backpack and a black aluminum baseball bat . He said he was n't going to hurt her , then forced a black box around her neck using something like a bike chain and locked it , the complaint said . He attached a lanyard with a green thumb drive and a plastic document sleeve containing a note . `` Count to 200 , '' he said , according to the complaint . `` I 'll be back . '' Pulver waited a few minutes , called out to him but got no response . She contacted her parents and asked for the police . After nearly 10 hours , tests concluded that the device was not a bomb . Peters is a globe-trotting investment banker who went to primary school in Hong Kong , attended college in Sydney , ran investments in Malaysia and spent time in the United States , where his ex-wife and three school-age children live , according to authorities and his attorney . CNN 's Jethro Mullen contributed to this report .
The case of Peters drew international news media attention . He attached a fake bomb to the victim and left a note demanding money , police say . Peter Paul Douglas was arrested in Sydney in August and extradited back to Sydney . He pleads guilty in a Australia court to aggravated breaking and entering .