According to state-owned energy company Petroperu, the cleaning of half a dozen beaches in Talara province has almost finished and work was planned to mitigate the impact on birds, fauna and commerce in the area, whose population relies on fishing and tourism.

The emergency measure will be in effect for 90 days, during which time the authorities must carry out recovery and remediation work, according to an environment ministry resolution cited late Wednesday by state news agency Andina.

The leak was detected last Friday on Las Capullanas beach when the crude oil was about to be loaded onto a tanker, the company said at the weekend without specifying the cause or amount of oil spilled.

The government's Environmental Assessment and Oversight Agency said the leaked oil extended over an area of 47 to 229 hectares (116 to 566 acres).

The public prosecutor's office launched an investigation Sunday against Petroperu for the alleged crime of environmental contamination that it said had affected the sea and shore along the South American nation's Pacific coastline.

"Birds and marine fauna were also found to be seriously affected," it said.