A St. Helena winery on Tuesday served a one-day suspension of its federal permit to sell wine as a result of a national investigation into consignment sales, an illegal practice in which a winery or wholesaler buys back bottles that retailers are unable to sell.

Modus Operandi Cellars shut down for the day as a result of a probe by the federal Alcohol and Tobacco Tax and Trade Bureau. The agency alleged that for over two years Modus Operandi did not charge wholesalers for its wine unless it had been sold to retailers.

In March, federal and state agents visited more than 30 wine-related businesses in Napa and Sonoma counties as part of the investigation.

Modus Operandi owner Jason Moore said in an email on Friday that his New York distributor was the “true villain” in the incident. Moore said it was his first vintage release in the wine business and that distributor dictated the terms of the agreement. He has since severed the contract with the distributor, he added.