Food safety tips: Centre for Food Safety's Principal Medical Officer Dr Tina Mok says it is not advisable to use oilfish for catering purposes.

The Centre for Food Safety is investigating 14 complaints from people who developed upset stomachs after eating some fish products labelled as "codfish".

The centre's inquiry found the fish in question may have been oilfish marketed as codfish. They were all bought from PARKnSHOP stores.

The retailer has stopped selling the fish products in question. The centre is now following up with the retailer concerning the source of the oilfish and labelling issues.

Speaking to the media today, the centre's Principal Medical Officer, Dr Tina Mok, said the symptoms were suspected to be related to the presence of indigestible wax ester in oilfish.

She said overseas studies found that consumption of oilfish may cause oily diarrhoea in some people. As such, it is not advisable to use oilfish for catering purposes.

She advised the trade to clearly label fish and fish products on sale for the public's easy identification.