Sao Paulo , Brazil ( CNN ) -- Brazil 's Federal Police agency said Thursday it 's investigating an oil spill at a site off the coast of Rio de Janeiro being explored by the U.S. oil company Chevron . The Federal Police 's Rio de Janeiro office said in a statement those responsible for the `` environmental accident in the Campos Basin '' could face sentences of up to five years in jail if found guilty . Brazil 's Oil and Gas Regulator ( ANP ) said Chevron reported a seepage in its offshore Frade project November 8 and said that between 200 and 330 barrels of oil per day leaked into the ocean . The resulting slick was about 163 square kilometers ( 100 square miles ) , Chevron said , and was situated about 120 km ( 75 miles ) off the coast of the state of Rio de Janeiro . Chevron moved to cap an assessment well Wednesday that it says is the source of the seepage , ANP said . Chevron told ANP that 18 vessels were on the scene to take care of the clean-up . But according to the Folha de Sao Paulo newspaper , Federal Police did a fly-over of the site Tuesday and saw only one vessel . `` The reports do not correspond with the reality of the facts , '' Fabio Scliar , from the police environment department , told Folha de Sao Paulo . `` I want to understand what happened . '' ANP said the spill is dispersing and moving away from the Brazilian coast , so it does not appear to threaten Rio 's world-famous beaches . But it does raise questions about how prepared Brazil is for the development of its offshore `` pre-salt '' deposits , which are expected to turn the country into a major oil exporter in the coming years .
The oil slick in Frade is about 120 km . Rio said an assessment well was the source of the spill . The spill does not appear to threaten ANP 's famed beaches , Chevron says .