Social workers have hit out at government figures on drug abuse among young people, claiming that despite an official downward trend, more youngsters are becoming addicted. The Central Registry of Drugs reported a drop in the number of cases involving under-21s from 4,289 in 1994 to 3,987 in 1995. In the first nine months of last year, the number of reported cases was 3,076 - about an eight per cent drop from 3,311 for the same period in 1995. But youth workers in outreach programmes said an unknown number of drug cases had been hidden from the Government since the Personal Data (Privacy) Ordinance was drafted a year ago. And some voluntary drug rehabilitation groups, which provide most of the services in the territory for young drug users, had stopped providing information because they failed to obtain government subsidies. The director of the Christian Zheng Sheng Association, Jacob Lam Hay-sing, admitted his organisation, which runs a rehabilitation service for teenage drug abusers, had not passed on figures for two years. 'We don't have the manpower to deal with statistics, and we're not the only ones who have stopped,' he said. Mr Lam, who believed the problem of drug abuse among youngsters had not improved, said Zheng Sheng alone came across more than 100 new cases a year. Sources said a meeting had been held between social workers and the Narcotics Division to discuss workers' concerns on submitting abusers' personal details. Legal advice has been sought by social workers who have yet to obtain guidelines from the Government, said a source. In 1995, 144 people aged under 21 died of substance abuse. 'The government figures cannot reflect the true picture,' said Rainbow Cheung Kam-hung, chairman of a working group on youth substance abuse at the Hong Kong Council of Social Service. Elsewhere, provision of such information was compulsory, she said.