U.S. law enforcement officials have reversed a decision to wind down an investigation into how news agencies handle the release of economic data to investors, concerned some sensitive information may have leaked into financial markets, a person familiar with the probe said on Wednesday.

The Wall Street Journal reported last Wednesday that Thomson Reuters Corp, the parent of Reuters News, Bloomberg LP and Dow Jones & Co., a unit of News Corp, were among the media companies under investigation.

The source who spoke to Reuters declined to provide details.

Reuters and the Wall Street Journal reported in January that law enforcement authorities had conducted an investigation into whether media companies facilitated insider trading by prematurely releasing market-sensitive data, but decided not to bring charges.

Media organizations are provided sensitive economic data during “lockups” in which they are not supposed to transmit any information until a set embargo time has lifted.

The Wall Street Journal reported on Wednesday that the FBI had been frustrated the Commodity Futures Trading Commission had not provided data sought by investigators. Citing officials familiar with the probe, it said the CFTC had since agreed to provide trading data and analysis to help the investigation.

“We are not aware of a current investigation nor any embargo violations,” said Ty Trippet, a spokesman for Bloomberg LP. A spokeswoman for Dow Jones, Paul Keve, said the government had not contacted Dow Jones about any criminal investigation. Thomson Reuters spokesman David Girardin declined to comment.

The FBI and CFTC did not immediately respond to requests for comment, while the SEC declined to comment.