Italian authorities are investigating incidents of adulterated wine, prompting the government to play down fears of another health scare like the one that hit mozzarella cheese last week.
A news magazine revealed that police were investigating the cheap end of the market for adding harmful chemicals into wine.
In a separate investigation at the luxury end, 600,000 bottles of vintage Brunello di Montalcino have been seized by investigators who suspect winemakers used grapes other than Sangiovese, the only ingredient allowed in the Tuscan wine, a favourite of US connoisseurs, L'Espresso magazine reported.
Police in the far north and south of Italy found evidence that cheap wine was being cut with sugar and sulphuric and hydrochloric acid, L'Espresso said.
It quoted investigators as saying 70 million litres of the adulterated wine may have been put on the market, with price tags of between 70 cents and 1 euro ($1-3) a bottle. In some cases only one fifth of the ingredients in the tainted 'wine' would have been grapes, L'Espresso said.
Little more than a week after several countries banned Italian buffalo mozzarella due to fears it was tainted with dioxins from illegal waste burning near Naples, the wine investigations again pushed the government to defend traditional Italian goods.
"Let's not have a storm in a wineglass," Agriculture Minister Paolo De Castro told La Stampa daily. "A few wrongdoers, who incidentally were already known to police for similar previous offences, certainly do not represent the image of the entire sector," he told reporters at Italy's main annual wine fair.
An Agriculture Ministry spokeswoman said the two cases were completely different and that none of the cheap wine was destined for export.
The adulteration of the cheap wine is a potential health hazard. The mixing of other grape varieties into Brunello, while posing no health risk, could dent its reputation in valuable export markets.
Despite record high euro-dollar exchange rates pushing up the price of exports, Italy's wine sector saw its foreign sales rise 12 percent in the first seven months of last year.
Italian wine outsells its French competitors in the United States two-to-one and a quarter of Brunello Di Montalcino's 6.5 million bottles annual production is sold in the United States.
Italian wine took years to recover from a scandal in the 1980s when a handful of producers added methanol - a cheap alcohol used in anti-freeze and for fuel - to boost the bite of their wines, killing at least 20 people.