THE Director of Public Prosecutions, Peter Nguyen QC, has directed that no criminal charges be brought against Vietnamese involved in a riot at Whitehead detention centre which caused police and Correctional Services Department (CSD) officers to be admitted to hospital. Mr Nguyen told police no proceedings should be taken against four Vietnamese identified in a police report as having been ringleaders. It is believed that he has justified the judgment on public policy grounds. The decision not to take action in relation to the May 20 riot confirms a South China Morning Post report last week which suggested the police investigation had been shelved for fear of inflaming the repatriation process and making martyrs of the attackers. This is despite the police file having video footage of the riot and witness statements to support charges. A police spokesman said last night: 'We have received advice, which is not to prosecute.' The Correctional Services Department Officers Association has protested to the Attorney-General, claiming the ruling would affect severely officer morale. 'The Legal Department decision has hit our staff's morale hard,' said Wong Wai-hung, association secretary. 'It also sends a worrying message to Vietnamese boat people while the public has to bear the consequences. 'It has also forfeited our chance for justice. 'The decision has shaken the public's confidence in Hong Kong laws and this can only lower everybody's trust in the Government.' The police force's Local Inspectors' Association has already indicated it will discuss the ruling's implications at an executive meeting this month. However, all force associations are outraged by the decision. Apart from official protests, officers are likely to consider the possibility of initiating private prosecutions. There is also the suspicion this decision reveals a government policy of not charging Vietnamese boat people except in the most exceptional circumstances. The Government will be criticised for double standards because of the charging of CSD officers last year for assault over a controversial operation on April 7 at Whitehead. Mr Nguyen's decision comes only a few days after a low-key operation to deport 85 refugees as part of the Orderly Repatriation Programme. They were returned to Hanoi on Tuesday but two CSD officers were injured in a punching incident. The Security Branch has been heavily involved in discussions over the affair. It believes some detainees actually want to be charged to delay their return. If they had to face court, their family members would remain in the territory beyond 1996 when the repatriation deadline expires. The Government is also concerned about paying compensation to Vietnamese on the basis they had been held against their will. The Post understands several senior police association figures have already secretly approached the Commissioner, Eddie Hui Ki-on, to express disquiet over problems in repatriation flights.