Chevron Corporation has never lacked for targets in its crusade against claims that it fouled Ecuador’s Amazon rainforest. On Friday the oil giant’s wrath fell on the highly pedigreed litigation consulting company H5, which it hopes to milk for information against yet another Chevron foe—the Gibraltar-based billionaire Russell DeLeon.

Chevron’s lawyers at Gibson, Dunn & Crutcher scored a major blow against their main enemy in the Amazon case in March, when a judge in New York ruled that attorney Steven Donziger procured a $9.5 billion Ecuadorean judgment against the company through fraud. More recently, Chevron forced Patton Boggs to renounce its decision to back Donziger, and to pay for its choice. Now Chevron is pursuing DeLeon, who heavily funded the Ecuador litigation, and it wants to force H5 to help build its case.