J Chandler and Company, who sell the tonic wine on behalf of Benedictine monks in Devon, have confirmed that year-on-year sales have increased in the two months since Jamieson praised Auchinleck Co-op’s decision to restrict or ban its sale.
Jim Wilson, a spokesman for the company, told Scotland on Sunday: "Sales of Buckfast have risen, and that is counter-productive to what the justice minister was trying to do. She has done herself no favours by criticising Buckfast. It makes up a tiny proportion (0.5%) of Scottish alcohol sales."
Wilson would not say by how much sales had jumped, but he added: "It is a substantial rise."
A spokesman for the Co-op also confirmed that year-on-year sales of Buckfast had risen in the past two months.
Jamieson’s remarks in February provoked a furious reaction among business leaders, who accused her of "tokenism".
J Chandler and Company condemned Jamieson’s remarks as a "cheap shot" and later threatened to sue the justice minister for defaming the Buckfast brand.
Jamieson, the MSP for Carrick, Cumnock and Doon Valley, wrote to the Scottish head of the Co-operative retail chain in January, urging the company to remove Buckfast from its Auchinleck store.
The firm agreed to impose selling restrictions, and the minister later urged other shopkeepers to follow suit.
"I would call on other off-licences to act as responsibly or ban Buckfast," she said at the time. "It is an unfortunate fact that off-licences can become the focus of antisocial behaviour and underage drinking.
"I welcome the Co-op’s recognition that there has been a problem and their decision to restrict the sale of Buckfast."
The Executive quickly distanced itself from Jamieson’s remarks, saying she had been acting in her capacity as a constituency MSP.
Wilson, however, said the Buckfast sales rise did not rule out the possibility that the company could take legal action against Jamieson. He said: "This rise has happened in the short term. Just as the sales appear to have had a boost, they could just as quickly fall - as happened to drinks like Hooch which also received negative coverage in the media."