Phumtham, who doubles as deputy PM, said he has instructed the Department of Internal Trade to ensure petrol stations do not shortchange consumers by giving them less petrol for the money paid or by modifying dispensers.
The minister was referring to several complaints posted on social media, in which people said they suspected they were being cheated.
Phumtham said the Commerce Ministry will join hands with the Energy Ministry to protect public interest. He added that the Energy Ministry directly supervises petrol stations, while the Commerce Ministry will be in charge of measuring devices or petrol dispensers.