The Fisheries Department has confirmed that canned fish products labelled as mackerel in Samut Sakhon were found to contain pla nil (tilapia), not mackerel as stated on the packaging.

Earlier suspicions that the fish might be blackchin tilapia were ruled out, the department said on Wednesday.

The department would submit its findings to the Food and Drug Administration (FDA) to support legal action against the manufacturer.

The FDA launched a full investigation after a Facebook video went viral showing a consumer questioning whether the canned fish he purchased — labelled as mackerel — actually contained mackerel.

FDA officials said that selling one type of fish while labelling it as another is consumer fraud.

The department said tilapia and blackchin tilapia belong to the same family but are distinct species. Media reports said the manufacturer admitted the product contained tilapia.

Blackchin tilapia is an African species that was originally imported to Thailand for research purposes but later found its way into local waterways, causing considerable damage to the ecosystem. 

Authorities inspected the factory on Wednesday.