Pre-mixed spirit and cocktail drinks sold in supermarkets contain up to nine teaspoons of sugar in just 250ml, according to experts, who say the beverages should be subject to the sugary drinks tax.

Such drinks have become increasingly popular in recent years but Action on Sugar, at Queen Mary University of London, found many are high in hidden sugar and calories and additionally lack information about their nutritional value.

Tesco strawberry daiquiri alcoholic frozen sorbet had the highest concentration of sugar, with 36 grams – nine teaspoons – in a 250ml bottle. Not far behind were Archers schnapps and lemonade, Malibu cola and Goslings Dark ‘n stormy black seal rum and ginger beer, which each contain eight teaspoons of sugar – more than in eight custard creams – in a 250ml container.

Action on Sugar says people consuming such beverages experience a “double whammy” to their health – from alcohol sugar – and it is absurd that they are exempt from the soft drinks industry levy.

Katherine Jenner, the group’s campaign director, said: “‘Gin in a tin’ has become a cultural phenomenon with these types of drinks often consumed ‘on the go’ and without a moment’s consideration to how much sugar and alcohol goes into making them.

“Even if you did want to know, you can’t make a healthy choice as only one in 10 of the products surveyed had enough information available. If consumers knew how much sugar was really in these drinks, would they still happily choose to drink their way to tooth decay, obesity and type 2 diabetes?”

Action on Sugar surveyed 202 drinks sold in-store and online. Out of 154 collected in-store, just 14 (9%) had information on sugar on the pack and only 63 (41%) had any form of nutritional information.

Due to the lack of information provided on some in-store packs, Action on Sugar commissioned independent laboratory analysis of 21 products, including WKD blue, which contained the most sugar, 15 teaspoons (59 grams in a 700ml bottle), or the equivalent of eating four iced doughnuts.

Tests on two TGI Fridays pre-mixed cocktails – a passion fruit martini and pink punk mojito – showed each had 12 teaspoons in a 500ml container.

The experts said levels of sugar were often unnecessarily high, pointing to the availability of alternatives with a lower content. For instance, Asda vodka, lime & lemonade had three grams of sugar in 250ml, while a 330ml can of Jack Daniels and no sugar cola eschews the white stuff altogether.

Action for Sugar says its findings illustrate the need for the government to extend the battle against obesity to the alcohol industry.

John Timothy, the chief executive of the industry-funded self-regulatory body, the Portman Group, said: “The industry has signed up to a number of Europe-wide voluntary commitments on nutrition which will give consumers access to information both on labels and through websites within the next two years. Many drinks producers also already offer lower calorie alternatives to give consumers greater choice.”

A Treasury spokeswoman said: “Pre-mixed spirit drinks are taxed through alcohol duties, which are at a significantly higher rate than the childhood obesity-focussed soft drinks industry levy. These raise over £12bn a year which helps pay for vital public services such as the NHS.”