THERE were calls yesterday to speed up the establishment of a regulatory body on scientifically assisted human reproduction as the territory's first sex selection centre opened for business. Legislative Councillors at the health services panel said the gender selection service could develop into other services, giving rise to ''dangerous'' ethical problems. Further concerns were raised when officials at the meeting failed to give an account of existing regulations on such services. The centre charges a minimum of $28,000 for couples who want to choose the sex of their baby through a process which separates male and female sperm. Asked what sorts of control the Government had on this kind of service, Deputy Secretary for Health and Welfare, Shelley Lau Lee Lai-kuen, said it did not fall within the Government's ambit. The Director of Health, Dr Lee Shiu-hung, said the Attorney-General's Chambers would have to be consulted before it was determined whether any action could be taken. But the Principal Assistant Secretary for Health and Welfare, Derek Gould, admitted that the Government could not interfere under existing legislation. Panel convenor Dr Leong Che-hung said the Government should step up controls because of the many uncertainties involved. ''How can we prove that the babies produced by this method are really related to their parents? If, unfortunately, the sex selection exercise fails, what can the consumers do then?'' ''Although the service does not show adverse effects now, how can we guarantee that the babies will grow healthily after 50 years?'' He accused the Government of acting too slowly to regulate problems arising from new technology. In its report in March, the working group on scientifically assisted human reproduction, chaired by Dr Leong, proposed the setting up of a statutory body. Consultation on the paper ended in June, but yesterday, Mrs Lau said the Government was still receiving submissions from the public. Noting that the technique of sex selection was not included in the consultation paper, Mrs Lau said the Government would consider another consultation round if necessary. But Dr Leong rejected the suggestion and said a statutory body should be formed to monitor the situation before it was too late. ''We have proposed the body overlook all sorts of problems related to scientific human reproduction. We are not going to set up individual bodies for each new issue arising,'' he said. Another legislator, Yeung Sum of the United Democrats, said the problem would have long-term effects. Mr Yeung said society would become ''very boring'' if all families decided to give birth to a single sex.