And now buyers of roller meal find they are getting around 9kg, or even less in some cases, as vendors carefully open the bag and scoop out a portion before selling the rest in the resealed bag.

In recent weeks efforts have been made to try and ensure that roller meal is sold in local shops to households, but it is difficult to exclude those who queue, sometimes after being tipped off by friends on the shop staff, to buy bags for resale in the black market.

The Herald bought three bags of roller meal all labelled 10kg, two from vendors and one from a city supermarket, and weighed them on two scales to ensure accuracy.

The other bag labelled "Sunny Roller Meal" weighed 9,6kg.

Established shops not only have their own rules about defrauding customers, but are also liable under the Trade Measures Act to random inspection from staff of the Ministry of Industry and Commerce who have the responsibility of ensuring that products on the market meet the stipulated standards.