The answer is yes.
Under Section 71 of Inland Revenue Ordinance (Hong Kong Ordinances Chapter 112), the commissioner has the authority to request a taxpayer to guarantee tax payment by securing the asset in the bank.
Also, based on this press release:
http://www.ird.gov.hk/chi/ppr/archives/010701c1.htm
IRD has frozen accounts in the past without a court order.
(One of the issue of a court-ordered freeze is only the court can unfreeze the account. If the unfreezing can be done by IRD, you can assume that the court has not been involved.)