Petrobras failed one part of a test needed to obtain a license to drill in the Foz do Amazonas basin, Brazil's environmental agency wrote in its review made public on Wednesday.
While the agency, called Ibama, said Petrobras passed the broader test, the technical report demanded that the firm resubmit its animal-rescue plan, listing it as a necessary step for its bid to drill in the ecologically sensitive region.
"The proposed plan is not capable of guaranteeing adequate actions to care for animals," Ibama wrote.
Petrobras did not immediately reply to requests for comment. Petrobras previously said it would resubmit the emergency response plan by Friday.
In a statement to Reuters, Ibama confirmed that Petrobras will need to present what was requested in the technical report, but exempted the firm from conducting another simulation prior to the granting of the license.
Despite the hurdle, the granting of the license is "inevitable," a high-ranking Petrobras executive, who asked not to be named in order to discuss sensitive matters, told Reuters.
The area in which Petrobras aims to drill, off the shore of the Amazonian state of Amapa, is considered Petrobras' most promising oil frontier, sharing geology with nearby Guyana, where Exxon Mobil is developing huge fields.
The simulated rescue led to three real-life incidents after Petrobras transported toys standing in for animals in a river at night to fulfill a 24-hour deadline to transport them to a veterinary center, said the report.
During the trip, a Petrobras boat became entangled in a fishing net. In another instance, one got stuck in a sandbank. There also was a near collision with another vessel, said Ibama.
Ibama staffers also noted that aircraft pilots lacked proper safety equipment from toxic substances that vaporize off animals contaminated with oil.
(Reporting by Fabio Teixeira, Marta Nogueira and Rodrigo Viga Gaier in Rio de Janeiro Editing by Matthew Lewis)
