Here is the Japanese justification, from http://icrwhale.org
AUSTRALIAN CUSTOMS PHOTOS MISLEAD THE PUBLIC
7 February 2008
The Institute of Cetacean Research has again condemned the Australian media for creating emotional propaganda to mislead the public.
A photo released by the Australian Government窶冱 Oceanic Viking has carried a headline alleging a mother minke and her calf were taken in the research programme.
The Director General of the ICR, Mr Minoru Morimoto said: 窶弋he photographs taken by the Oceanic Viking and which major Australian newspapers published today shows two minke whales, but they are not a mother and her calf as claimed by the media.窶・
窶廾ur research program requires random sampling of the Antarctic population, and therefore there will be a range of sizes. It is necessary to conduct random sampling of the Antarctic minke population to obtain accurate statistical data.窶・
The smaller of the two whales in the Australian Customs photograph was 5.3 metres in length, while the larger one was 8.3 metres. Both whales were female, and both were not lactating.
窶弋he Government of Australia窶冱 photographs and the media reports have created a dangerous emotional propaganda that could cause serious damage to the relationship between our two countries. It is important the Australian public is not misled into believing false information,窶・he said.