Thieves have stolen about 30,000 bottles of wine worth an estimated £4.2 million (€5 million, $5.8 million) from Marchesi Antinori, Italy's largest family-run producer, in what the company says is the biggest theft of its kind the country has seen.

'A theft of this scale and value has certainly never occurred in Italy,' chief executive Renzo Cotarella said.

At least seven masked men raided the company's storage warehouse in Cortona, in the Tuscan province of Arezzo, on Saturday, 3 October, while staff were preparing a shipment for customers abroad. Surveillance footage showed the group disabling the alarms and cameras before using the winery's own forklift trucks to load thousands of cases onto two lorries.

The theft was discovered when staff returned on Monday morning, and the company went public on Friday, 9 October, as it appealed for help recovering the wine.

Between 8,000 and 10,000 of the stolen bottles were Solaia, one of Italy's most sought-after labels, along with quantities of Tignanello and Guado al Tasso. The bottles retail from about €150 to €500 each, roughly £125 to £420 ($175 to $580), and the rarest vintages can fetch several thousand euros, the equivalent of several thousand pounds, a bottle.

Tignanello and Solaia rank among Italy's original super Tuscans, the Sangiovese-based reds that producers began blending with French grapes such as Cabernet Sauvignon in the 1970s, outside the region's traditional rules. Guado al Tasso is a prized red from the Bolgheri coast. Together they turned once-overlooked Tuscan estates into some of the biggest names in fine wine.

Antinori said the haul was possible because the wine had already been packed and prepared for shipment to foreign distributors, which let the thieves clear a huge volume of high-value stock in one fast operation.

The careful choice of labels, the company believes, points to a well-organised group with specialist wine knowledge and possibly inside information. Antinori added that the raid may rank among the largest of its kind anywhere, not just in Italy, by volume and value.

Antinori has alerted buyers in Italy and overseas, urging them to treat any offer made outside official channels with suspicion. Cotarella said he hoped investigators could trace the bottles through Tuscany's dense network of road cameras. 'Two trucks full of merchandise can't just disappear into thin air,' he said.

He also questioned how so many bottles could be sold abroad without drawing attention. Buying stolen goods is a criminal offence in Italy, and a sudden surge of rare Tuscan wine on the secondary market would be likely to alarm collectors, dealers, and auction houses.

Moving 30,000 bottles at once, without leaving a trail, would be close to impossible, which is why Antinori is counting on the scale of the raid to work against the thieves.

The theft caps a run of raids on Italian cellars this year. In Piedmont, two wineries were hit within roughly three months. In early July, thieves took around 3,000 bottles of sparkling wine from Castello Banfi's Piedmont facility.

Then, overnight on 16 September, four masked men broke into the Conterno Fantino winery in Monforte d'Alba and left about three hours later with roughly 3,000 bottles of Barolo, again using the estate's own forklift to shift the cases. Conterno Fantino urged wine traders to call the Carabinieri if offered bottles through unusual channels.

The pattern points to thieves shifting from taking a few rare bottles at restaurants or private cellars to emptying whole warehouses, where producers store large stocks of finished wine ready for export.

Such wine is also difficult to recover. Unlike most stolen goods, it can be opened and drunk, and once bottles are dispersed and sold on, tracing them becomes far harder.

Marchesi Antinori traces its winemaking to 1385, when Giovanni di Piero Antinori joined Florence's winemakers' guild. The Florence-based company is now run by the 26th generation of the family, exports to about 170 countries, and reported revenue of €263 million, about £223 million or $305 million, last year.

Italian police are investigating, and no arrests have so far been reported. Antinori said it was working with the authorities to track the stolen wine before it could reach buyers, and remained hopeful that at least some of the 30,000 bottles would be found.