A teenager who came to Hong Kong eight years ago when his adoptive parents pretended he was their natural son lost his court battle yesterday to avoid being sent back to the mainland. Yu Ah Wing, 19, an apprentice, was 11 when brought to Hong Kong. He has lived here ever since, attending school, making friends and getting himself a job. But in the Court of First Instance, Mr Justice Frank Stock said there were no legal grounds for blocking the Director of Immigration's decision. 'There can be little doubt that his removal, if effected, would be a source of very considerable trauma to him and to his adoptive family,' the judge said. 'No feeling soul would wish other than that the coming trauma for this applicant, and that of others who fall into a similar predicament, could be relieved. 'But the Director of Immigration has to operate within a setting infinitely more complex than that, and has no doubt all too often to harden his heart in the proper exercise of his statutory duties.' Mr Yu was born a week after his adoptive parents' third natural son. In 1979, Mr Yu's adoptive father came to Hong Kong and his wife joined him in 1986. That year, their natural son sneaked into Hong Kong. Before he came his parents applied for a one-way permit in his name. When that arrived in 1991, they used it to bring Mr Yu into Hong Kong instead. The deception was not discovered until 1995 when the false one-way permit was used in an attempt to obtain an ID card for Mr Yu. His lawyers claimed there were compassionate grounds upon which Mr Yu should be allowed to stay, arguing he had lost contact with his family on the mainland. They also challenged the legal basis for ordering his removal and claimed he had not received justice. But Mr Justice Stock said there were no grounds which would justify him in interfering with the Director of Immigration's decision. It was for the director to assess whether the compassionate grounds justified the exceptional course of allowing Mr Yu to stay. 'He is well placed to judge what would constitute such exceptional compassionate circumstances,' Mr Justice Stock said.