A barman at Bogarts, in North Street, was caught selling bottles of WKD during a test purchase carried out by the Peterborough Evening Partnership on March 7.

Despite telling a Peterborough City Council licensing sub-committee on Wednesday that the oversight was a "genuine mistake", Carl Melillo was told that Bogarts would be stripped of its premises licence.

The licence will be suspended for three months, or until Cambridgeshire police, which triggered the review of the licence, is satisfied that comprehensive training on under-age sales has been given to staff.

Mr Melillo was also told that upon re-opening, he must ensure that a personal licence holder is on the premises at all times when alcohol is for sale.

Defending the barman, Mr Melillo said: "The chap who did the serving made a genuine mistake. I have at all times insisted that they must ask for ID if there is any doubt about age. At Christmas 2007, we passed a similar check by the authority with flying colours.

"This was a genuine mistake and the barman is sorry. All I can do is apologise on his behalf."

The latest decision is a further blow for Bogarts, coming a month after a bid to demolish the business and turn it into apartments was turned down.

Mr Melillo said Bogarts was already closed because of the economic "times we are in at the moment".

In response to a question from committee member councillor Charles Swift about whether or not there were plans to re-open Bogarts, Mr Melillo said: "It is very difficult to keep the business running.

"I cannot say how long it will be closed, but, hopefully, not for too long."

Mr Melillo added that he was looking at options to rent the building, or put it up for sale.

Although it is not listed, Bogarts – which dates back to 1837 – was saved from demolition after members of the city council's planning and environmental protection committee said the building should be preserved.

After 40 minutes of deliberation, committee chairman Cllr Yvonne Lowndes said a three-month ban on trading would be enforced, as recommended by Cambridgeshire police.

When asked for his reaction to the ruling, Mr Melillo declined to comment.

The council's licensing enforcement officer Darren Dolby said: "We hope that the suspension will remind all retailers of alcohol in Peterborough of the need to ensure that they put in place an adequate level of staff training to prevent any sales of alcohol to people under the age of 18, and the potential consequences if they do not."