Dr Karen Lee Man-yee, an assistant professor teaching constitutional law at Shue Yan University, said one question was whether an indigenous man who became a woman would lose his inheritance rights or whether a woman who became a man would gain them.

"For matrimonial matters, if a male-to-female transsexual has married and had children before she has a sex-change operation, should her duty as a 'father' continue after the operation?" Lee asked.

"Also, only women can be victims of rape under Hong Kong law. So does the identity of a victim extend to transsexual from now."

Dinusha Panditaratne, adjunct assistant professor of law at the Chinese University, said that if post-operative transsexuals had the right to marry, this implied that they also had the associated rights of divorce, inheritance and adoption.

"But the court did not explicitly say so - instead, it asked the legislature to consider all these issues together."

Panditaratne praised the ruling as "reassuring for the general protection of rights" as it made clear that individual rights "should not be at the mercy of what the majority thinks".

But she did not think the court had intended to open the door to same-sex marriage.

Heung Yee Kuk president and former Law Society president Junius Ho Kwan-yiu said there was no current provision in the New Territories small-house policy excluding female-to-male transsexuals from the right to build a three-storey house.

"The logical deduction from the judgment today is that he is entitled, as long as the person is at least 18 years old and descended through the male line from a resident in 1898 of a recognised village," he said.

University of Hong Kong gender expert Dr Sam Winter said the ruling gave no safeguards to transsexual men or to pre-operative or non-operative transsexuals, unlike in Britain.