Two Prosecco producers were allegedly caught adding sugar to their wines, a practice which is forbidden in the Italian region, Forbes reports.

Although the producers were not named, they are reportedly within the tightly-regulated Denominazione di Origine Controllata e Garantita (DOCG) classification, considered some of the highest-quality sparkling wine in the region. Only 25 percent of Prosecco production receives DOCG designation.

Exactly how the unidentified “culprits were caught” is unclear, John Hinman, partner in Hinman & Carmichael law firm says, but it is “usually an employee or a competitor that turns them into the authorities.”

If the allegations are true, the producers will be “brought to justice,” Forbes reports.

Adding sugar to wine boosts its fermentable sugar content, which ultimately raises the wine’s alcohol level. Doing so indicates a producer is unable to extract the proper amount of sugar from grapes during production.

A reason for the breach could be pressure to produce more wine in the region, where short vintages have led to limited supply of ripe grapes.