A Texas federal judge on Monday canceled a deposition scheduled for Tuesday (Dec. 13) by ExxonMobil Corp. of Massachusetts Attorney General (AG) Maura Healey regarding a probe into the supermajor’s fossil fuels research.

U.S. District Judge Ed Kinkeade of the Northern District of Texas issued the one-sentence order with no explanation after Healey filed a petition for mandamus with the U.S. Court of Appeals for the Fifth Circuit.

Kinkeade instead gave lawyers for Healey and ExxonMobil until Jan. 4 to submits briefs stating their positions as to why or why not the deposition should take place in Texas.

Healey’s probe, begun in April, is part of a wide-ranging case launched by New York AG Eric Schneiderman, who last year launched an investigation claiming the company deceived consumers and investors about its internal research into the potential effects caused by fossil fuels.

If the multi-state probe were to prevail, the company could be forced to disclose internal research dating back decades.

Although Healey filed her lawsuit in Massachusetts, Kinkeade last month ordered her to come to Texas for the deposition, which was considered an unusual decision. The judge cited concerns about whether Healey launched the investigation “with bias or prejudgment” about what the investigation would discover.

Healey’s lawyers argued that requiring the deposition in Dallas would “set a troubling precedent by allowing the target of a state government investigation to confound and effectively halt state law enforcement efforts by filing suit in the target’s favored federal forum and permitting the target to ‘investigate the investigator.'”