(Reuters) – A subset of key and highly sensitive U.S. inflation data was inadvertently published about 30 minutes ahead of its scheduled release on Wednesday, the Bureau of Labor Statistics said, and a full investigation to the latest data-management misstep at the agency is underway.

“In advance of today’s (Consumer Price Index) and Real Earnings releases, BLS inadvertently loaded a subset of files to the website approximately 30 minutes prior to the release,” BLS said in a notice posted to its website late on Wednesday. “BLS has alerted the Office of Management and Budget and (Department of Labor’s) Office of the Inspector General of the incident. BLS takes its data security seriously and is conducting a full investigation into its procedures and controls to ensure the incident is not repeated.”

The agency did not disclose which data points were released early.

The monthly CPI report is among the most followed economic data series published by the U.S. government.

A guide post for economists, investors and Federal Reserve policymakers about the level and trajectory of inflation, it stands as one of the most critical data events each month because it provides a key signal about the direction of interest rates set by the U.S. central bank.

As such, its release – typically scheduled at 8:30 a.m. ET (1230 GMT) on a mid-month weekday – is an event that often triggers the movement of trillions of dollars in assets around the globe.

The announcement comes just months after an agency economist was reported to have been sharing undisclosed technical calculations underlying some of the data from the CPI series with private-sector economists.

Wednesday’s CPI data for April came in below market-based expectations and triggered a broad rally in stock and bond prices on the premise that it would allow the Fed to proceed with interest rate cuts later this year, something that had been cast into doubt after a run of higher-than-expected inflation readings through the first quarter.

It does not appear that the accidental release on Wednesday morning around 8 a.m. ET (1200 GMT) triggered a notable market response. The yield on the 2-year Treasury note, highly sensitive to Fed policy expectations, was steady near 4.79% in that window until the full release at 8:30, when it dropped sharply on the lower-than-expected CPI reading.

(Reporting By Dan Burns; Editing by Chizu Nomiyama)