WATCHDOGS found that a shocking 97 per cent of pints of beer sold locally were short measures.
Undercover trading standards officers bought 38 pints of lager and bitter from 19 local pubs recently - and only one of the pubs served a full pint.
In total, 26 of the pints they bought were up to five per cent short of a full pint and another 11 were up to 10 per cent short.
Legally, only five per cent leeway is permitted and, in the worst cases, written warnings were issued.
Forty-seven pubs were also visited to check that branded spirits were the genuine product.
Officers checked that well known branded spirits such as Smirnoff Vodka, Bacardi Rum and Gordons Gin, were not being replaced with cheaper products - which has been a regular issue in the past.
They tested 93 spirit drinks in total, all of which were found to be the genuine product.
Coun Richard McCauley, St Helens Council’s cabinet member for environmental protection and safer communities, said: “Even though times are difficult for our public houses, their customers should get what they pay for.
“When beer is around £3 per pint, serving 10 per cent less than the full pint is short changing the customer by 30p.
“I’m pleased to see that the work our trading standards team have done has paid off. Substitution of branded spirits with a cheaper product is no longer commonplace in the area.”