Alcohol Concern has raised doubts over Tesco's commitment to responsible retailing after the supermarket this week sold wine at 4p below duty plus VAT.

Tesco was selling a six-bottle case online for £12.78 equivalent to £2.13 a bottle as part of its 25% off Wine Festival. As duty plus VAT on a bottle of wine is £2.17, it was making up the shortfall by paying the government the extra 4p on each bottle sold on top of supplier, transport and retail costs.

The deal was removed from Tesco's website on Wednesday. "This was a pricing error affecting only a handful of lines for a very short period," it said. "The price was corrected as soon as the error was spotted."

Tesco, which signed up to the Responsibility Deal on public health, last year backed coalition plans to ban the sale of alcohol below the cost of duty plus VAT. "We acknowledge our own sales of alcohol might be impacted but if these measures have the desired effect of helping to reduce harmful drinking, it will be worth it," corporate affairs director Lucy Neville-Rolfe said at the time.

Alcohol Concern chief executive Don Shenker said the latest deal "calls into question to what extent Tesco really wants to support a harm-free agenda".

He added: "If you're incentivising people to buy more than they normally would, there is more incentive to drink. Since Tesco recognises the link between pricing and binge drinking, it's deeply worrying they're selling bottles of wine for £2.13."

A spokesman for the British Medical Association also attacked supermarkets selling booze "so cheaply".