The National Environment Agency (NEA) has found rodent activity at 14 food establishments in popular shopping mall, Marina Square.
Traces of rat activity was also detected at a bin centre in the mall.
The findings come after a dead rat was discovered by an unsuspecting diner at the mall's Hotpot Culture restaurant last month.
NEA followed up with investigations after the find was made public.
In an email reply to Chinese evening daily, Lianhe Wanbao, NEA said checks were conducted on restaurants near and around Hotpot Culture. Rat droppings were discovered in the establishments' false ceilings.
The NEA also said enforcement action will be taken against three premises - one was found with rat droppings, and another two for being dirty.
The rest were reminded to ensure good housekeeping, proper food storage and waste management. An advisory on pest prevention and control measures were also distributed to the store operators.
Hotpot Culture remains closed for now, after it was ordered by NEA to suspend business on Jan 9.
Two rats were caught on Jan 11 as intensive pest control treatment was carried out in the restaurant.
A thorough inspection in October 2014, which covered 77 licensed food shops and stalls in the mall, resulted in enforcement action being taken against 12 stores with evidence of rodent activity and four food premises found to have food scraps on the floor.