Suspected killer arrested after he picked up package containing HK$100,000, police say A man was in police custody last night after being arrested on suspicion of killing a missing airline ground crew member during a robbery and days later demanding a HK$100,000 ransom for her. A 24-year-old decoration worker was arrested on Thursday night after he allegedly picked up the ransom in Kowloon and officers followed him to his public housing flat in Tai Po. Police also arrested six of his friends - a 16-year-old girl and five males - in a series of raids in Tai Po and Kwun Tong. After helping with inquiries, they were released unconditionally yesterday afternoon. Following the arrests, police discovered the body of 21-year-old Yau Hiu-yin in the dead end of an underground nullah that connects to the Lam Tsuen River in Tai Po before dawn yesterday. Police said Yau was waylaid in Tai Po while on the way home from work at the airport to Kam Shan village at about 1.30am on Thursday last week. She was the daughter of the village head, Yau Kam-ming. 'Preliminary investigation revealed that she was robbed of her belongings and forced to reveal the PIN number of her bank card when she was threatened with a paper cutter,' a police source said. 'Somehow the holdup developed into the killing. The victim was then pushed into the river and dragged into the dead end of the nullah.' About HK$60,000 had been withdrawn from her bank account with the stolen card, police said. Yau was reported missing to police on the same day after she failed to return home. 'A few days later, somebody sent a text message via her mobile phone to her boyfriend demanding a ransom for her release,' the same police source said. Her boyfriend then alerted police. 'The HK$100,000 ransom was reached after days of negotiation via mobile phone and the money was arranged to be placed in a location on the afternoon of Thursday.' Officers arrested the 24-year-old man after he picked up the money and returned to his Tai Po home on the same night. Police said the ransom and Yau's stolen property, including HK$60,000 in cash, were recovered from the suspect's home. Senior Superintendent Eric Kong Sai-cheong, head of New Territories North regional crime unit, said investigation showed the ransom was demanded after the victim was killed. 'The body has been badly decomposed. At this stage, no superficial injury has been found on the deceased,' he said, adding that an autopsy would be carried out today. But the police source said: 'The victim is thought to have been strangled to death in the robbery. We're still investigating whether she was killed in a struggle.' Yesterday morning, the hooded and handcuffed suspect, wearing shorts and a pair of slippers, was escorted by police to the river. In the afternoon, weeping relatives of Yau burned incense and paper offerings at the river. The suspect was being detained in Tai Po police station last night and no charge had been laid. Yau joined Jardine Airport Services as a passenger services officer in mid-2006. Her colleagues called her 'Yen'. The company's human resources director, Anita Lo Siu-yin, described Yau as a 'hardworking employee with very good performance'. 'We're shocked and saddened over her death. She was a sweet girl and had a good relationship with her colleagues,' she said adding that more than 20 colleagues needed counselling after learning of Yau's death.