(Reuters) - Hilcorp Energy [HILCO.UL] on Tuesday said it contained a leak from an abandoned flow line at its Lake Washington Field in Plaquemines Parish, Louisiana on Monday.

Around 30 to 100 barrels of oil were released and cleanup operations have begun, the exploration and production company said, adding that the cause of the leak was unknown.

The U.S. Coast Guard had earlier reported it was responding to a crude oil spill from an abandoned flow line near Lake Grande Ecaille, Louisiana.