THE number of recorded child sexual abuse cases has more than doubled, but social workers claim this might only be the tip of the iceberg. The Social Welfare Department's Protective Services Unit recorded 15 active child sexual abuse cases being dealt with by government and non-government agencies as at December 1991, but on September 30 last year the number of cases had more than doubled to 32. Both government and non-government social workers say the reality could be worse, because the department and other authorities often record active or ongoing cases. They do not include cases which have been dealt with and resolved before they tally the number at the year end. Exact calculations are also hindered by some authorities not separating general child abuse from child sexual abuse cases. Against Child Abuse recorded an increase of 19 cases, from 113 in their 1990/91 financial year to 132 in the 1991/92 financial year. But these figures, which only show a general picture of child abuse, cannot reflect the level of child sexual abuses. Caritas recorded an increase in child sexual abuse cases to about 10 last year. The group's Family Service Co-ordinator, Miss Angie Lai Sung-yee, said: ''Only a few cases have been recorded in past years, maybe 13 in three years, but last year the number increased considerably.'' Recorded cases involved victims ranging from two years old to 13. Miss Lai said the increase in recorded cases could be an indicator that more people were seeking help. ''We may actually be mobilising the public through prevention work and encouraging them to seek help,'' she said. But she claimed Caritas social workers had reached their limit in resources in providing counselling. The Against Child Abuse Director, Mrs Priscilla Lui Tsang Sun-kai, also said her team had ''reached the limit of what we can handle''. ''This type of work is intensified so if our social workers took on any more the cases could end up in files in a drawer.'' The group's workers also conduct public education and man the hotlines. They conducted 149 follow-up investigations and referred 45 to the Social Welfare Department for follow-up action. The Social Welfare Department's Protective Services Unit co-ordinator, Miss Li Yuk-san, also said the increase in recorded cases could reflect the willingness to seek help. ''Frontline social workers are more aware of how to bring sexual problems into the proper channels, and clients themselves, who do not want to make the problem into a police case, may be willing to accept help. ''The families fear exposing the problem could lead to a family breakdown, because most cases involve a father and daughter. But if the mothers are caring and positive and protective, they will want to protect the child more by seeking help.'' Miss Li said adult victims were also coming forward to seek help on dealing with ''the shadow left on how they deal with relationships with people especially in sexual relationships''. Meanwhile, Caritas is holding a child sexual abuse prevention workshop for five to 10-year-olds at the Duke of Windsor Social Service building in Wan Chai today . It will include role plays to deal with meeting a stranger, and talks about the body. Workshop co-ordinator Ms Tsao Suk-ching said children needed to be taught how to protect themselves. ''Many parents don't tell their children about the parts of their body because it is traditional that parents feel embarrassed to give their children sex education. Little boys are sometimes told their private part is a little birdie - then they wonder if their birdie is going to fly away. ''They need to be taught names for parts of their body and how to protect themselves by saying they do not want to be touched, or telling another adult that they did not like the way someone touched them.'' She said too many parents thought they could protect their children from strangers, but many of the abusers were adults the child knew or even relatives.