Japan has summoned senior diplomats to complain about an activist attack on its Antarctic whaling fleet using mild acid made from rotten butter.

The Sea Shepherd group carried out the attack from their boat, the Steve Irwin, which last docked in Australia and is registered in the Netherlands.

Tokyo officials have protested to the ambassadors of both those nations.

They have also pledged to raise the issue at this week's meeting of the International Whaling Commission (IWC).

"It's not permissible to use violence to try to force through one's opinion," AFP news agency quoted Foreign Minister Masahiko Komura as saying.

The IWC will meet in London for a three-day informal gathering in an attempt to break the deadlock between pro-whaling and anti-whaling nations.

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