An aunt has admitted to killing her infant nephew and hiding the body in the family washing machine in Shanghai. Shanghai police said on its official Sina Weibo on Wednesday night that the four-month old baby who disappeared from his cradle on Sunday morning had been found dead in the washing machine at home. His aunt has admitted to killing him because of "psychological imbalances arising out of family disputes", the police said. The news came after four days of wide media attention and searches for the baby. The family sold breakfast in a food market on the outskirt of Shanghai and their home on the ground floor doubled as the restaurant, leading to fears the infant was taken when the adults were busy serving customers. Originally from Anhui province, the extended family of eight lived together: the boy and his parents, grandparents, and aunt and uncle with a baby daughter, according to Shanghai's Labour Daily . The father and uncle were out working on the morning when the boy went missing, the newspaper said. The police gave no more details in its Weibo post and said the investigation was continuing. CCTV said online the boy was found in a plastic bag, and apparently suffocated. People have expressed shock to the news online, speculating the aunt acted out of jealousy as she had not given birth to a male baby, the traditionally preferred gender on the mainland. There was a similar public outcry in early September when news emerged that a boy had his eyes gouged out in an attack by his aunt. The six-year-old boy, Guo Bin, is expected to leave the hospital in the coming weeks. The death in Shanghai was also the second "washing machine fatality" on the mainland in two months. In September, two young sisters in Jiangxi died after they reportedly crawled into a washing machine and accidentally turned it on.