Nine importers were fined a total of $23,000 on Wednesday for illegally importing fresh vegetables.

Two were fined an additional $600 each for illegally importing processed food for sale, said the Singapore Food Agency (SFA).

From March to August, officers from SFA and the former Agri-Food and Veterinary Authority detected 2,848kg of undeclared and underdeclared fresh vegetables.

They also found 340kg of undeclared processed food in the batches of vegetables imported by the nine offenders.

The illegal batches were seized. Vegetables confiscated during the inspections included leaf mustard, Chinese celery and spring onion.

SFA said that illegally imported food products come from unknown sources and pose a food safety risk.

It added that food imports must meet the agency's requirements and food safety standards.

Food can be imported only by licensed importers, and every batch must be declared and accompanied by a valid import permit.

Offenders who illegally import fresh fruit and vegetables can be fined up to $10,000, jailed for up to three years, or both. The illegal import of processed food can draw a fine of up to $1,000. Repeat offenders can be fined up to $2,000.