Brazilian President Luiz Inacio Lula da Silva said the Petrobras computers stolen in january contained state secrets. - File

Brazilian police said yesterday they believe the theft of important information from the state oil company was probably corporate espionage.

The chief of federal police said yesterday that investigators had ruled out common theft as the cause of the disappearance this month of computers and hard drives belonging to state-controlled oil giant Petroleo Brasileiro SA, or Petrobras.

No common thief

"It wasn't common theft," Valdinho Jacinto Caetano said at a news conference. "Common thieves wouldn't steal hard drives. They wanted specific information."

Two days earlier, Brazilian President Luiz Inacio Lula da Silva said information stolen from Brazil's state-run oil company was related to two huge new offshore petroleum finds - the Tupi and Jupiter petroleum fields.

"This is a serious thing that we are investigating," said a statement from his office.

Caetano said there was a "flaw in security" when the computers were shipped from an offshore rig to Petrobras offices last month.

Silva said it is too soon to determine whether the information was stolen by a group planning to pass information about Tupi and Jupiter to foreign companies or governments.

Police say the four laptops and two hard drives were in the possession of Houston-based oil services company Halliburton Company when they were stolen last month while being transported from an offshore rig in the Santos Basin exploration area where Tupi and Jupiter are located, to the city of Macae in Rio de Janeiro state, where much of Petrobras' offshore exploration effort is centered .

No details on missing data

Petrobras has refused to give details about the missing data, except to say it was "confidential information" stolen from "equipment and materials that contain important information for the company."

But Petrobras told authorities the information affects Brazil's national interests, police said.

News of the theft was made public last week, but Silva's comments were the first official confirmation that the data stolen was related to the big petroleum finds.

Halliburton referred questions to Petrobras, which said only that the computer equipment was under guard of a subcontractor it declined to name.

Petrobras in November announced the discovery of an ultra-deep Atlantic Ocean field called Tupi with as much of eight billion barrels of light crude.

The chief executive of Britain's BG Group PLC, which also has a stake in the field, said this month that the field's production could reach one million barrels of oil equi-valent a day when fully developed.

Last month, Petrobras also said it had discovered a huge natural gas reserve dubbed Jupiter off the coast of Rio de Janeiro that could be as big as the recently discovered Tupi oil field, but it did not provide detailed potential production figures.