Hong Kong's top court ruled on Wednesday that a British lesbian should be granted a spousal visa, upholding a lower court's decision, in a landmark judgment that could open the door for expatriates' same-sex partners to move to the financial hub.

The British woman, identified only as QT in court, sued the director of immigration in 2014 after she was denied a spousal visa that would have granted her resident status and allowed her to work without the need for a separate visa.

The woman and her partner, a dual British and South African national identified only as SS who was offered work in Hong Kong, had entered into a civil partnership in Britain.