The Wall Street Journal has been banned from the next two Budget lockups after enraging the Treasury with an embargo breach this year.

The Treasury will not allow the WSJ to attend future Budget briefings in Wellington or other major fiscal updates until 2025.

The punishment, announced this afternoon, came even though the journalist alerted Treasury officials inside the lockup soon after the embargo breach.

A WSJ journalist on May 19 sent information from the restricted briefing venue an hour before the 2pm embargo.

Budget lockups in The Beehive last several hours, intended to give journalists time to read and analyse screeds of information before the Finance Minister delivers the Budget.

Treasury said any breach of Budget information security was taken very seriously.

"We communicate this very clearly to all attendees of the Budget restricted briefing."

The Treasury said it contacted the WSJ after the alleged breach and asked for an explanation.

"WSJ has told us that a failsafe against accidental transmission [in] the journalist's usual work laptop was not installed in the laptop they had taken into the Budget 2022 lockup."

The WSJ said the journalist also left a mobile hotspot running, which meant the story could be transmitted to the Journal's publishing desk.

The newspaper also told Treasury officials the editor handling the story skipped one of the protocols that would have provided a failsafe against accidental publication.

The story went on the Dow Jones website about one hour before the embargo lifted.

Nine restricted briefing events were expected between now and Budget 2025. The WSJ and the specific, unnamed reporter have been banned from all those events.

The ban included half-year economic and fiscal updates and the pre-election economic and fiscal update.

"These consequences for WSJ and the specific journalist are proportionate with the degree of seriousness of the embargo breach and the need to reinforce to everyone the importance of compliance with the lockup protocols."

BusinessDesk in May said Dow Jones news wires carried the story, providing details of information that financial markets used to trade foreign exchange, bond and equities.

The WSJ, based in New York City, has more than 3.5 million print and online subscribers and is generally regarded as the most influential business publication in the world.

News Corp, which owns the WSJ through subsidiary Dow Jones, has been approached for comment.