Leicester has been "flooded" with imports of cheap branded soft drinks from Eastern Europe.
The two-litre bottles of Coke, Fanta and Pepsi are made in Hungary or Slovakia and feature foreign language labels.
One retailer, Subhash Varambhia, who runs Snutch Newsagents in Leicester, tried stocking the products but gave up after customers complained about their quality.
"I was buying it for 50p rather than the 90-95p that I normally pay at the cash and carry," said Subhash. "I sold it at the normal full price of £1.55, but some people said that it didn't taste the same as normal, so I stopped. It was worth a try, but I don't want to risk losing customers."
He added that many other stores in the Leicester area are selling the soft drinks, but that someone had tipped off Trading Standards about his store. Officers told him that foreign products needed an ingredients list in English on packs and he was subsequently given a strip of sticky labels to put on each bottle by his supplier, Quality Foods.
A spokesman for Leicester Trading Standards said that a retailer at the Pennywise store in Wigston Magna, near Leicester, had been fined last year for stocking products - including Fanta and Sprite - without English labels.
"There's a legal requirement that there should be certain information on pack so that consumers can make an informed choice," he said.