Around 150,000 of the city's army of domestic helpers are from Indonesia, the world's most populous Muslim-majority country.
Against a backdrop of growing religious conservatism at home, a small number of militant maids has emerged, according to a report from the Jakarta-based Institute for Policy Analysis of Conflict (IPAC).
But rights activists and the Indonesian Muslim community in Hong Kong said they were unaware of radicals and fear that reported links with IS would breed unfair suspicion.
"Some of these women were drawn by jihadi boyfriends they met online," says IPAC analyst Nava Nuraniyah. "But some joined ISIS as a path to empowerment."
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A string of abuse cases has highlighted the exploitation of maids in Hong Kong by unscrupulous employment agencies which confiscate their passports, claim their wages and keep them in the dark about their rights.
But the IPAC report said ill-treatment did not seem to have played a direct role in radicalisation, although it had led to the establishment of an Islamic advocacy group to act as a kind of union.
It told the story of one woman who turned to radicalism after years of turmoil in her personal life and became a key player in helping Indonesian jihadis get to Syria, sometimes via Hong Kong.
A handful of maids ended up going to Syria themselves, said IPAC, a leading think-tank which has published numerous reports on conflicts in Southeast Asia.
Hong Kong media has previously reported about IS supporters leafleting Indonesian domestic helpers as they gathered in public spaces across the city on Sundays, their day off.
The Indonesian community in Hong Kong has tripled in the past 17 years due to the demand for domestic helpers, and religious teaching and prayer groups have grown alongside it.
But Indonesian migrant rights activist and former domestic helper Eni Lestari said while the threat of extremism was always a possibility, she was unaware of IS supporters among them.