The Japanese government plans to expand the number of whale species it can catch, ostensibly for scientific research, to include the sperm whale and Bryde's whale, sources close to the situation said Wednesday.

Japan, which says it has been catching minke whales for more than 10 years "for research," has submitted a proposal to the Scientific Committee of the International Whaling Commission to add the two species, sources in Japan and abroad said.

The IWC imposed a global ban on commercial whaling in 1986, but the IWC Convention stipulates the right of countries to catch whales for scientific purposes upon informing the IWC of their plans.