An exercise was carried out between 2012 and last year to check that all pumps in filling stations were properly calibrated, Consumer Affairs Minister Helena Dalli said.
Replying to a parliamentary question by Censu Galea (PN) she said the exercise was aimed primarily at informing the station owners on measurement quality.
Those pumps which were found to be 'under-reading' were rectified so that the variance did not exceed 10ml per 20 litres issued. They were then re-sealed.
No legal action against the owners was taken or needed.