Underused facilities for young offenders may be used to house adult prisoners to resolve chronic overcrowding in prisons, the commissioner of correctional services suggested yesterday. Kwok Leung-ming said he had set up a taskforce to study the possibility of regrouping penal institutions and would come up with a solution by the end of the year. He said correctional institutions for young offenders - those aged 14 to 20 - had an 18 to 20 per cent vacancy rate in the past few years. 'Now would be a good time to consider how to better utilise their facilities,' he said. Mr Kwok also said studies were under way on whether mainland prostitutes could serve their sentences across the border. In mid-2004, Tai Tam Centre for Women exceeded capacity by 257 per cent. The average prison population last year was 12,390, but there are only about 11,000 places, department figures show. Mr Kwok believed overcrowding could be greatly relieved by 2010, when the Lo Wu Correctional Institution would be redeveloped into three penal institutions providing additional places for 1,200 inmates. The existing institution has a capacity of only 200. The redevelopment plan, endorsed by the Legislative Council Finance Committee in July, would develop the institution into two medium-security facilities and one minimum-security institution. Legco security panel chairman James To Kun-sun said jailing mainland prostitutes in Hong Kong still acted as a deterrent. He also said resources could be better used if the department could focus more on the right groups, such as young inmates, for rehabilitation.