Police have stepped up patrols on the exclusive streets of The Peak after a Swiss businessman and his family were held up at knifepoint and robbed by intruders who fled with HK$40,000 and valuables including jewellery. The three masked robbers forced the man's wife to withdraw money from a nearby ATM while they held her husband, elderly mother and six-week-old daughter captive in their three-storey house in Mount Austin Road. Last night, a search was still under way for the three men, suspected to be Filipinos. The family's ordeal began when the intruders prised open a rear door of their home in the Mount Austin House luxury development at about 2.30am yesterday. Investigators believe the men climbed down a hill at the rear to avoid security guards at the estate's front entrance. The couple heard a noise when the culprits were ransacking the ground-floor living room. 'When they went to check, they were threatened with knives and subdued,' a police officer said. 'The couple, the woman's mother and an Indonesian helper were tied up. The wife was then ordered to go alone to withdraw money from an automatic teller machine.' The bound victims were forced into one of the bedrooms before the robbers escaped with the cash, jewellery, four computers and four mobile phones. Last night, police were still calculating the value of the stolen property. Officers were called to the house when the family untied themselves and the wife called police at 4.45am. The 36-year-old businessman suffered arm injuries and his wife's 64-year-old mother, who suffered leg injuries, was so shocked by her ordeal that she had to be admitted to hospital. The others were unhurt. The crime rate on The Peak has been low since a spate of break-ins in 2002 by mainlanders recruited to raid wealthy homes in Hong Kong. A police spokesman said there had been two reports of burglaries so far this year, with the one in September being the first since early 2008. 'Camouflaged officers from our rural patrol units will be deployed to enhance patrol and surveillance in the area,' a police officer said. Road blocks would also be set up at nights.