January's figure of 22.1 billion patacas ($2.76 billion) was worse than analyst expectations of a drop of around 2 percent - estimates that were made prior to the implementation of visitor restrictions last week.

Some analysts forecast a decline of at least 30% for as long as visiting restrictions are in place.

Transport links with mainland China have been curtailed, with dozens of flights and ferry services cancelled. The local government has also extended the Lunar New Year break to the end of the week, keeping banks and businesses closed as the death toll from the virus outbreak topped 250 and hundreds of new cases were confirmed.

(Reporting by Farah Master)