In Fife, during Fair Measure Fortnight, officers bought 42 drinks and found 19 short, 21 over and just two correctly poured. In Angus, of eight drinks purchased, just one was found to be correct.

Drinkers in Perth fared better, with three of four measures bought exceeding the stipulated measure.

Nationally, the results of the investigation were little better, with 45% of measures tested containing less than the stated amount of alcohol.

The situation with short measures was deemed so bad in Dundee that officers intend reporting three city licensees to the Procurator Fiscal following their findings.

Dundee-based Ken Daly, chairman of the Society of Chief Officers of Trading Standards in Scotland, said he did not believe unscrupulous landlords were deliberately short-changing customers.

However, he said the findings were extremely concerning and, as a result, the Servewise licensee training programme in Dundee is being reviewed to ensure appropriate training is given in the pouring of open measures.

Mr Daly said, “This is a very disappointing outcome and the results certainly justify local authorities carrying out this sort of project. The extremes of measures at both ends of the spectrum show we need to work with the licensed trade to train staff to provide accurate measures to consumers.

“It is a matter of concern that just over 10% of measures tested were completely accurate.

“For health and safety reasons, as well as the obvious fair measure, Scottish consumers need to have confidence in the accuracy of measures of all types of alcohol that are supplied in licensed premises.”

Officers from 25 Scottish local authorities were involved in the investigation last month, and a total of 193 pubs were visited. Of 343 samples purchased, only 39 were on target while a staggering 155 were found to be short.

SCOTSS said today the spread of under and over measures was fairly consistent nationally and in the majority of cases the discrepancy amounted to less than 4% of the volume of the drink. In most cases where measures were inaccurate, the publican was issued with guidance on how to ensure correct measures were dispensed. However, reports were sent to the Procurator Fiscal in 22 cases nationally where the level of short measure was deemed significant.

Colin Wilkinson, secretary of the Scottish Licensed Trade Association said, “The survey emphasises the need for licensees and staff to receive proper training. The SLTA looks forward to working with Trading Standards to review and update existing training to make sure licensees’ legal responsibilities are met.”

Dundee Licensed Trade Association vice chairwoman Sheena Thomson said she was surprised by the findings but was sure there was no deliberate intention to defraud.

She said she was pleased changes were being made to the Servewise scheme to ensure the use of open measures was covered in training given to licensees.

Sheena said, “It is obviously very disappointing. The vast majority of pubs take their duties very seriously and most drinks are dispensed in optics of 25 or 35mls.

“Obviously when drinks are short they are being done in thimble measures and possibly, that is an issue of training. I am quite sure the vast majority of licensees are not trying to rip people off.”