Tokyo -  Tokyo police sought arrest warrants on Monday against three members of the Sea Shepherd Conservation Society who interfered with Japan's research whaling mission in February last year.

In the first-ever attempt by Japanese authorities to press criminal charges for obstruction of its whaling programme, the Metropolitan Police Department plans to list two US nationals and one British citizen on an international wanted list, according to media reports.

A 41-year-old US environmental activist allegedly interfered with Japan's whaling in the Antarctic Ocean on February 12 last year by throwing 18 flares, nine of which spewed flames, according to the investigation.

A 30-year-old US national and a 28-year-old Briton reportedly disturbed the Japanese ship Kaiko Maru's operation by getting a rope caught in its propeller.

Japan's Chief Cabinet Secretary Nobutaka Machimura criticized the environmental group for threatening the lives of the ship's crew.

"No matter what their belief is on whaling, no physical obstruction that threatens people's lives should be forgiven," he said.

Machimura said the police action should have been expected and called on Sea Shepherd and other organizations to refrain from violence in their anti-whaling campaigns.

Police are also investigating a separate case, where Sea Shepherd activists allegedly tossed flares and several bottles of rotten butter, commonly known as butyric acid, and inflicted injuries on Nisshin Maru crew members.