The head of the Hei Ling Chau drug-treatment prison off Lantau lost $100,000 worth of valuables during Sunday night's riot, he said yesterday. But Acting Senior Superintendent Mui Kwok-keung - said to have been one of the rioters' key targets because of his perceived preferential treatment of Vietnamese inmates - said he had no plans to seek a transfer. Mr Mui said a diamond ring, some jade ornaments and Rolex and Tudor watches had disappeared during the seven-hour rampage in which 35 people were injured. 'They might have been thrown or buried somewhere on the island. I also had a mobile phone smashed and some cash has gone missing,' he said. Mr Mui said he and his wife were preparing to have dinner at their quarters just before 7pm when the emergency alarm was activated after a dispute broke out between Vietnamese and local inmates. He told his wife to leave the house and stay near the pier at Hei Ling Chau before he went to the scene, where 400 inmates were involved at the height of the riot. The disturbance was sparked by a verbal dispute between local and Vietnamese inmates. Prisoners besieged a cell where the 13 Vietnamese inmates were taking shelter and threw burning objects into the dormitory. All 13 Vietnamese inmates were injured, including one who was last night still in a serious condition after suffering burns to 50 per cent of his body. Mr Mui said he was determined to stay on in his post. 'The allegations are unfair,' the prison chief said. 'Vietnamese inmates are treated in the same way as the locals. I will not seek a transfer. My officers have been supporting me. The incident has happened and I think I've a responsibility to help the reconstruction.' He said he was still checking his total losses, estimated at between $80,000 and $100,000. Other officers' quarters were also ransacked. Mr Mui, 47, has been with the Correctional Services Department for 25 years and in charge of the centre for about six months. He was injured while holding the first round of negotiations with more than 100 local inmates but says they did not assault him. 'The local inmates demanded I hand over five Vietnamese inmates involved in the assault against the locals,' he said. 'I could not agree to that. Some inmates supported me and tried to push me away from the crowd, saying I would not be able to resolve the situation by talks.' But Mr Mui said the pushes were mistaken by his officers as an attempt to hold him hostage. When they rushed to offer protection, scuffles broke out between them and the inmates. He had been injured while trying to stop inmates hitting his officers. He rejected allegations that he had given preferential treatment to Vietnamese inmates by having them build gardens and fish ponds at the centre to improve the fung shui. Mr Mui said the construction of the garden was part of work therapy for drug addicts and that some local inmates had also been chosen for the work. 'I have dozens of photographs recording the construction process. I could submit them to the inquiry board investigating the incident,' he said. Mr Mui said the garden had nothing to do with fung shui and it was simply an attempt to make Hei Ling Chau more environmentally friendly.