Court documents have inadvertently revealed details about an oil market informant, reports Financial Times.

The U.S. Commodity Futures Trading Commission has asked a judge to block those documents so as not to deter other whistleblowers. The defendants don’t yet know the informant’s name, just his or her employer.

The case involves Arcadia Petroleum and affiliates, and commenced in May 2011. CFTC has accused “the companies owned by Norwegian shipping billionaire John Fredriksen of creating a false impression of oil scarcity as crude hurtled towards a record $147 a barrel” in 2008, FT reports.

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