U.S.-based activist group Sea Shepherd Conservation Society has reached a court-mediated settlement in which it is permanently prevented from "physically attacking" Japanese whaling vessels and crew, Japan's Institute of Cetacean Research said Tuesday.

Despite the settlement, Sea Shepherd Australia said later Tuesday that the development will not affect its activities in the Southern Ocean as it was reached over a case fought in a U.S. court.

"Sea Shepherd Australia remains committed to upholding the Australia Federal Court ruling banning the slaughter of whales in the Australian Whale Sanctuary," said Jeff Hansen, managing director of Sea Shepherd Australia, in a statement.