A man was arrested after he tied up his drug addict girlfriend with a bicycle chain and locked her in their Pat Heung village house in an attempt to force her to quit drugs. The woman's ordeal began at 11am after her 25-year-old live-in boyfriend chained her and then left her at the house in Ng Ka Tsuen in Kam Sheung Road, police said. At 3pm, the 28-year-old woman called police and said she was tied up by her boyfriend after an argument. Police and firemen went to the scene and found the house was padlocked. They broke in and found the woman chained to a window frame. 'We immediately untied her and sent her to North District Hospital for a check-up,' a police spokesman said. The woman was later discharged. Police said the woman told them she had a heated argument with the man about their relationship. The boyfriend had beaten her right shoulder with a wooden bar, chained her and left, she said. 'Officers left the house and left a note, asking the owner of the house to contact us,' the spokesman said. 'Her boyfriend finally contacted us late at night and we arrested him for alleged unlawful detention.' A police source said the man tied up the woman because he wanted to help her quit drugs. Neighbours said the two had lived together for a few years and had a two-year-old daughter. The man refused to allow the woman to see her daughter unless she quit drugs. One neighbour said the man had also locked the woman inside the house on Monday but released her when he returned home. 'They even went shopping in Tin Shui Wai this morning,' the neighbour said. The man was being detained by police overnight.