U.S. oil giant Chevron on Tuesday admitted that the leak from a well operated by the company off Brazil's southeastern coast has not stopped.

Addressing the public audience in Macae in the state of Rio de Janeiro, Chevron's environment supervisor Luiz Alberto Pimenta Borges said he could not give the specific time when the oil spill could be stopped.

"The amount of oil is becoming gradually smaller," he said.

"We expect to have total control of the matter some time in the future. I cannot tell when because we are still evaluating the amount of oil to know how exactly it reached the surface," Borges said.

Borges said the leak, which started early in November, was the result of unexpected pressure over the company's drilling equipment.

He said a total of 2,400 barrels of oil had leaked from the well though the leaking reservoir had been closed, revealing that the company is still having problems with residual oil.

Chevron had already been fined 28 million U.S. dollars for the oil spill and banned to drill in the area until investigations into the accident end. Meanwhile, the prosecutor's office in Rio is suing the company for a compensation of 81 million U.S. dollars.