An expert witness called by Australia in its case against Japan at the International Court of Justice says he does not believe Japan's whaling programme is for scientific purposes.
Professor Marc Mangel from the University of California, a specialist in applied mathematics and statistics, told the hearing at The Hague on Thursday that Japan's research programmes have only considered lethal means to collect data.
"Lethal take can only make sense if we have a question that needs to be answered... a meaningful question," Professor Mangel said.
Australia is arguing Japan's practice of catching and killing nearly 1000 whales per year for research disguises commercial whaling and contravenes international law.
The ABC reports Japan and Australia have both agreed to be bound by court's verdict.
Japan says the whales it kills each year contribute to research designed to establish if whale stocks are recovering from previous over-hunting. Japanese consumers consider the meat is a delicacy.