RIO DE JANEIRO — More than 2,600 barrels of oil may have spilled into the Atlantic ocean because of a leak at an offshore Chevron drilling site, Brazil's environmental protection agency said Friday.
Officials think 200 to 330 barrels of oil leaked each day from Nov. 8 through Tuesday, the Ibama agency said in a statement on its website.
Chevron has said that 400 to 650 barrels of oil in total leaked into the ocean. Officials are still investigating the exact cause of the leak, which has been almost entirely contained, but the Ibama statement said it was a result of the drilling.
A spokesman for Brazil's Federal Police, which has opened an investigation into the spill, said that Chevron "drilled about 500 meters (1,640 feet) farther than they were licensed to do." The official spoke on condition of anonymity as he was not authorized to discuss the matter.
The leak occurred at a drilling site about 230 miles (370 kilometers) northeast of Rio de Janeiro.
Rio state Environment Minister Carlos Minc said earlier he was sure the leak was larger than Chevron estimated and he called for more transparency from the company.
"We can't trivialize this," he told the Globo TV network. "It's really serious and we don't yet know all the consequences."
The oil slick, which is moving away from the coast, grew to 11 miles (18 kilometers), according to the Ibama statement. Most of the oil is concentrated around the drilling rig and is about 3 feet (1 meter) thick.
Marine life in the area of the spill will be affected by the leak, Minc said, adding that whales are migrating from north to south through the spill area.
Chevron said "current estimates place the volume of the oil sheen on the ocean surface to be less than 65 barrels."
The company has 18 ships working on a rotating basis to collect oil off the surface and monitor the slick.
The drilling contractor for the well is Transocean — the owner of the Deepwater Horizon rig that oil company BP was leasing at the time of last year's Gulf of Mexico oil spill, the largest in U.S. history.
Chevron said that cementing operations are taking place so that the well is plugged. ANP said in a note on its website that "the first stage of cementing, to permanently abandon the well, was successfully completed." The regulator says that the success of permanently plugging the well will be known "in the coming days."
ANP also said underwater footage showed that a "residual leakage flow" was continuing, but that "the oil slick continues moving away from the coast and is being dispersed, as desired."
Fabio Scliar, head of the Federal Police department's environmental affairs division, which is investigating the case, said those responsible would held accountable.
"There is no doubt that a crime occurred. The spill comes from the drilling activity. What interests me now is to find who is responsible," Scliar was quoted by the Folha de S. Paulo newspaper as saying.