A mentally disabled right-of-abode seeker was deported to the mainland yesterday, hours after Hong Kong's top court turned down his appeal to be allowed to stay. Cheung Hoi-sang, 25, who has a mental age of 13 according to his solicitor, was sent to the Lowu checkpoint at about 1pm from Victoria Prison, where he has been held since April 13. His parents met their son, who they said had never travelled alone, before his mother took him back to their home in Shilong town, Dongguan. His mother, Cheung Wong Yuet-yuen, broke down in tears after crossing the border. 'My son does not know how to take care of himself,' she said. 'He's got lost three times in Hong Kong and we've spent hours looking for him. I'm so worried that my son will end up like Yu Man-hon.' Autistic boy Man-hon, 15, ran away from his mother and disappeared on the mainland in August 2000 after being wrongly sent back to Shenzhen. Mrs Cheung said the family would have to hire a helper to care for their son, as she and her husband worked at restaurants in the SAR to support the family. Her son was put in the care of a helper after his mother settled in Hong Kong with his younger brother in 1993, but he sneaked into the SAR in March 1997. Mr Cheung said he had no idea how he would cope without his parents: 'I don't know what to do. My happiest time in Hong Kong has been having meals with my family.' Mr Cheung was removed after Mr Justice Patrick Chan Siu-oi of the Court of Final Appeal granted an application made by the Director of Immigration to deport him immediately. Barrister Daniel Wan, for the director, said no medical certificate had been submitted to prove Mr Cheung's mental disability. His solicitor, Robert Brook, accepted Mr Wan's view but called for bail of seven days so a medical examination could be arranged. He said the mental age of 13 was an estimate by Mr Cheung's parents and the young man needed constant care. 'I don't understand the Government. I don't understand how people sit back and let the Government do this,' Mr Brook said. Mr Cheung was arrested on April 12 in Central and was taken to Victoria Prison. Mrs Cheung visited her son every day and stayed outside the prison for a few hours to join Father Franco Mella, who was staging a hunger strike against the detention. Father Mella, who ended his 10-day fast yesterday, said he was shocked by the court ruling. An Immigration Department spokesman said they decided not to give Mr Cheung the normal one-week grace period of stay before repatriation in case he went into hiding.