Australia has released graphic pictures of minke whales caught by a Japanese hunt in the Antarctic.
Japan says the whale hunt is legal and for research purposes
Canberra claimed the pictures, taken by customs officers tracking the hunt, show a harpooned mother and calf being dragged from the sea.
Japan denied that claim and called the pictures "emotional propaganda".
Australian environment minister Peter Garrett said he hoped the "distressing" images would boost international opposition to the whale hunt.
Mr Garrett said they contradicted Japan's long-standing claim that the hunt was legal and for scientific research purposes.
"It is explicitly clear from these images that this is indiscriminate killing of whales, where you have a whale and its calf killed in this way," he said.
"And to claim that this is in any way scientific is to continue the charade that has surrounded this issue from day one."
Japan's Institute for Cetacean Research (ICR), which is supported by the government, released a statement accusing Australia of misleading the public by spreading "false information".
Canberra and the Australian media have "created a dangerous emotional propaganda that could cause serious damage to the relationship between our two countries," said ICR Director General Minoru Morimoto.
A statement on the ICR website said the minke whales, both female, were 5.3m (17.4ft) and 8.3m (27.2ft) respectively but were not a mother and calf.
"It is necessary to conduct random sampling of the Antarctic minke population to obtain accurate statistical data," said Mr Morimoto.
Japan had planned to kill up to 900 minke whales and 50 fin whales during the expedition.
Australian Customs Minister Bob Debus said the pictures, taken by the crew of the surveillance vessel the Oceanic Viking, could be used as evidence in an international court case to end the hunt.
Hunting has only recently resumed after environmental activists from Greenpeace and Sea Shepherd disrupted the operation for three weeks.
Two crew members from the Sea Shepherd ship, the Steve Irwin, boarded the Yushin Maru 2 factory ship and remained on board for four days.