A survey into purported unfair beer pricing found that of 16 food and beverage outlets in Singapore, only three did not raise prices above the calculated excise increase stated by the Ministry of Finance.

Although the calculated increase for the price of a a 633ml bottle of Tiger beer was about 40 cents, the Consumers Association of Singapore (Case) discovered that many vendors were found to have increased the price above that limit.

One was even found to have upped the price by $1.30.

Case officers carried out the survey over the past two weeks, posing as customers at outlets in areas such as Serangoon, Bedok, Yishun, Hougang and Ang Mo Kio.

Initially 11 establishments which had been complained about were chosen for the survey after customers said they had lifted prices by over a dollar. A further survey was carried out to gauge the prices of other outlets in districts surrounding them.

The consumer watchdog said it based its research on the price of a 633ml bottle of Tiger as it is one of the most common types of beer that customers drink at coffeeshops.

Last month, the Ministry of Trade and Industry (MTI) warned businesses about profiteering from the increase in liquor duties. In a statement, MTI also said it will work closely with Case and the Competition Commission of Singapore to "monitor the market for any unfair pricing and coordinated price hikes which are anti-competitive".

Case president Lim Biow Chuan urged consumers to make "informed choices" when they purchase alcohol. He also urged businesses to have "clear and transparent sale policies and not to take advantage of consumers by raising prices without justification for the increase".