The 612 Humanitarian Relief Fund said it made the decision because the Alliance for True Democracy, the group whose bank account it uses, said it would no longer execute its payment requests.
The latest development came after the national security police announced they were investigating the two organisations and ordered them to hand over information, including details of donors and recipients.
“We are deeply conscious of the impact of this turn of events on current applications, and will do our best to look for all possible solutions and relief,” the fund said in a statement on Facebook.
Legal advice is being sought on whether donations made recently can be refunded, it added.
The fund said as of Monday, it had about HK$7.2 million in the bank account.