Public hospitals yesterday agreed to almost double the fee for non-local women giving birth in emergency wards, to HK$90,000 - but mainland agencies are already giving mothers instructions on using fake documents to book a maternity bed. The Hospital Authority's decision came a day after the Food and Health Bureau confirmed that no mainland woman not married to a local man would be allowed to give birth at private hospitals next year. Chief executive-elect Leung Chun-ying said last week that there would be a quota of 'zero' for mainland births. Pregnant mainland women will have to show their marriage certificate and their husband's Hong Kong identity card to book a bed at private obstetrics departments. But agencies in Shenzhen are offering fake marriage certificates. One agency told the Post it was offering certificates for only 280 yuan (HK$344) per copy. 'It's nearly impossible to recognise a fake certificate by sight,' the agent said. 'Unless Hong Kong authorities check with the mainland civil-affairs bureau displayed on the certificate, they won't be able to find out it's a fake.' Women would also need access to a man's ID card, either real or fake. Another Shenzhen agency, Dawn Proligerous Information Consulting Service, said it would not book beds for women using fake marriage certificates, but a consultant with the company said Hong Kong's rules on birth certificates made the trick possible, at least in theory. That is because new mothers do not have to put the name of their husband on the birth certificate and can use the name of the child's biological father. Health Secretary Dr York Chow Yat-ngok said it was possible women could use forged documents, and agreed it would be hard to catch fakes. But Chow said the burden of proving a document was genuine would fall on the couples involved. 'Providing false documents is a criminal act and can result in imprisonment,' he said.