The government-run Vinmonopolet said sales were broadly flat in January and February, but they have been on a strong upward curve since the coronavirus lockdown began in mid-March.

Travel restrictions have prevented Norwegians from purchasing cheaper alcohol abroad, while bars and restaurants were shut down for several weeks.

The on-trade is starting to reopen at reduced capacity levels, but travel restrictions could last for months, and Vinmonopolet is likely to enjoy strong volume growth throughout 2020.

Volumes increased 44% in May, and June is expected to be another busy month for the monopoly stores.

Vinmonopolet spokesman Jens Nordahl said: “Sales have increased, but not more than could be expected in light of the halt to border trade, duty-free stores and restaurants, bars and cafes.”

Norway will open up a travel corridor with Denmark from June 15, but it will maintain a quarantine with Sweden, which is a popular destination for Norwegians seeking to buy cheaper wine and spirits.

Sweden has taken a unique approach to the Covid-19 pandemic, as it is one of the few countries that did not impose a lockdown. That has seen it maintain the usual pattern of alcoholic beverage sales.

Finland has followed a similar trajectory to Norway. State-owned monopoly retailer Alko reported 23% year-on-year sales growth in April, following the decision to restrict international travel and shut bars and restaurants on April 4.