Brazilian President Dilma Rouseff is calling for an investigation into an offshore oil leak her country's oil regulators say was caused by Chevron Brazil's drilling operations several hundred miles away from Rio de Janeiro.

Speaking to Reuters today, Floriano Carvalho, the director of Brazil's energy authority ANP, said Chevron's drilling had increased pressure on the ocean floor and caused a crack through which the oil is escaping.

A Brazilian embassy spokesperson corroborated ANP's findings Monday.

Investigations have lead Chevron Brasil and Brazilian government agencies to suspect that an appraisal well drilled at the Frade Field last week is contributing to the oil being expressed through these seep lines, read a Chevron release. This appraisal well was closed in at surface on Nov. 9 as a part of the precautionary suspension of drilling activities implemented by the company.

On Sunday, the company received permission by the Brazilian government to plug the well responsible for the leak. Ultimately, the well will be cemented shut, according to the company's statement.

Chevron officials as of Sunday, an estimated 400 to 650 barrels of oil have seeped into the ocean. Crews are working to contain the oil sheen, which has drifted roughly 74 miles from the country's coastline.

As a precaution, drilling operations have been suspended in the area.

A company statement released Sunday suggested there may be more than one seep through which oil is being released into the ocean.

The company said Saturday that underwater vehicles had located the leak, which is near the company's drilling area in their Frade project. The company was drilling roughly 230 miles from Rio de Janeiro at approximately 3,800 feet.

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