Tesco has been fined £300,000 after admitting it misled customers over whether strawberries on sale were genuinely "half price".
Trading standards officers said the £1.99 strawberries on sale in Sheldon, Birmingham, in 2011 had not been for sale at £3.99 long enough.
The store charged the same amounts at its other stores in England and Wales.
Tesco admitted four counts of unfair commercial practice at Birmingham Crown Court.
Judge Michael Chambers said the case was "shocking by its very nature" because consumers had a "high degree of trust" in national chains.
He said the promotion was "patently wrong and misleading".
Tesco has apologised for what happened.
The supermarket was told it would also have to pay £65,000 in costs.
The judge said he had taken into account the financial damage caused to Tesco's reputation when considering the fine.
'Employee error'
Birmingham City Council, which brought the prosecution, said Tesco had sold strawberries for one week each at £3.99 and then £2.99 in 2011.
It said the supermarket then sold the fruit at £1.99 over June, July and August 2011, labelling the 400g containers as "half price".
Under the pricing practices guide, the length of the new lower price sale should not be longer than the old higher price was available for.
The same prices were used at all the supermarket's 2,300 stores in England and Wales. The case did not apply to Scotland and Northern Ireland because they come under different legal jurisdictions.
Trading standards officials said it was not only a victory for Birmingham customers, "it also has wider benefits for all consumers across the country".
Sajeela Naseer, head of trading standards at Birmingham City Council, said: "It was the council's case, confirmed by Tesco's guilty pleas today, that this was a misleading offer which deceived the purchasers of strawberries over many weeks during the summer of 2011.
The court heard Tesco had apologised and said it accepted it had fallen well below its normally high standards.
The supermarket said it was not a case of "deliberate mis-selling" but an error made by an individual employee.
In a statement, Tesco said it "apologised sincerely for this mistake".
It added: "We sell over 40,000 products in our stores, with thousands on promotion at any one time, but even one mistake is one too many."
"Since then, to make sure this doesn't happen again we've given colleagues additional training and reminded them of their responsibilities to ensure we always adhere to the guidelines on pricing."
Trading standards officers said the £1.99 strawberries on sale in Sheldon, Birmingham, in 2011 had not been for sale at £3.99 long enough.
The store charged the same amounts at its other stores in England and Wales.
Tesco admitted four counts of unfair commercial practice at Birmingham Crown Court.
Judge Michael Chambers said the case was "shocking by its very nature" because consumers had a "high degree of trust" in national chains.
He said the promotion was "patently wrong and misleading".
Tesco has apologised for what happened.
The supermarket was told it would also have to pay £65,000 in costs.
The judge said he had taken into account the financial damage caused to Tesco's reputation when considering the fine.
'Employee error'
Birmingham City Council, which brought the prosecution, said Tesco had sold strawberries for one week each at £3.99 and then £2.99 in 2011.
It said the supermarket then sold the fruit at £1.99 over June, July and August 2011, labelling the 400g containers as "half price".
Under the pricing practices guide, the length of the new lower price sale should not be longer than the old higher price was available for.
The same prices were used at all the supermarket's 2,300 stores in England and Wales. The case did not apply to Scotland and Northern Ireland because they come under different legal jurisdictions.
Trading standards officials said it was not only a victory for Birmingham customers, "it also has wider benefits for all consumers across the country".
Sajeela Naseer, head of trading standards at Birmingham City Council, said: "It was the council's case, confirmed by Tesco's guilty pleas today, that this was a misleading offer which deceived the purchasers of strawberries over many weeks during the summer of 2011.
The court heard Tesco had apologised and said it accepted it had fallen well below its normally high standards.
The supermarket said it was not a case of "deliberate mis-selling" but an error made by an individual employee.
In a statement, Tesco said it "apologised sincerely for this mistake".
It added: "We sell over 40,000 products in our stores, with thousands on promotion at any one time, but even one mistake is one too many."
"Since then, to make sure this doesn't happen again we've given colleagues additional training and reminded them of their responsibilities to ensure we always adhere to the guidelines on pricing."
