By Richard Black
Environment correspondent, BBC News website, St Kitts
Australia is to present what it says is proof that Japan's scientific whaling programme is cruel, to the meeting of the International Whaling Commission.
Ian Campbell described the footage as "absolutely inhumane"
Environmentalists who filmed Japanese boats whaling in the Antarctic say that some animals took 30 minutes to die. Japan says these cases are exceptions.
Caribbean nations have criticised the West for a "colonial" attitude.
Australian Environment Minister Ian Campbell is due to present the report during Sunday's deliberations.
Early sessions on Sunday saw a fourth straight defeat for Japan, this time on a motion calling for the abolition of the Southern Ocean whale sanctuary.
Japan currently conducts "scientific" whaling there as it is permitted to do under IWC rules, but commercial hunting in the Antarctic would not be possible while the sanctuary exists.
Time to death
During the last Antarctic whaling season, which saw a doubling of Japan's annual "scientific" catch to just over 1,000, Greenpeace filmed a number of kills at close range.
The footage has now been analysed by scientists working with another conservation group, the International Fund for Animal Welfare (Ifaw).
"We found that for one whale the time to death was over half an hour; we found that the average time to death was 10 minutes," said Ifaw's Vassili Papastavrou, "and in two out of the 16 occasions, asphyxiation was the likely form of death."
The whales were asphyxiated, he said, because harpoons entered their bodies near the tail and the animals were held upside down in the water.
"Back in the 1950s, it was recognised that whaling was inhumane, and really nothing very much has changed since then," Mr Papastavrou told BBC News.
Harpooned whales often take a long time to die, activists say
"It's simply impossible for the harpooner to hit the whale close enough to the brain to ensure a reliable clean kill in all cases."
Japan maintains these examples are the exception rather than the rule.
"The time to death for the majority of whales is less than 30 seconds," said Glenn Inwood, a spokesman for the Japanese delegation.
"Japan takes the issue of time to death very seriously, and is working together with Norway to improve the humane side of whaling."
The IWC does not have firm guidelines on time to death; but a past chair of its scientific committee, Doug DeMaster from the US National Oceanic and Atmospheric Administration (Noaa), said the general goal was "insensibility as soon as possible".
Australia's environment minister Ian Campbell described the footage as "absolutely inhumane and quite disgusting.
"It is a horrendous thing... it is absolutely abysmal, it is wrong and it has to stop," he told reporters.
Japan's deputy whaling commissioner Joji Morishita countered by pinpointing Australia's annual cull of millions of kangaroos.
"I just wonder if the minister knows how long it will take for kangaroos to die in his country?" he said.
Representatives from five Caribbean states and two African nations castigated Western nations over what they labelled a "colonial attitude".
The self-styled "pro-conservation" bloc, informally led by Australia, New Zealand and the US, has regularly said that Caribbean states vote with Japan because they are instructed to do so as a condition of receiving Japanese aid.
Japan has equally regularly refuted the allegation; and in a news conference on Sunday, the Caribbean delegates went on the offensive.
"Poor black countries are treated differently; it is a shame that race has to come into it in 2006, but it all goes back to when we were colonised," said Claris Charles, minister of education and labour for Grenada and a former whaling commissioner for the Caribbean state.
"I am sure that at some point in time that if the very countries which state 'whales should not be used' were to find some way in which whales can contribute to their national economies, they will sing a different song; so let us not be hypocritical here."
There was specific criticism for Britain's Fisheries Minister Ben Bradshaw.
Before the IWC meeting, he suggested that western consumers might begin taking the positions of Caribbean nations on whaling into account when planning where to spend their money.
"It is the people who will ultimately decide if they believe that killing endangered species is acceptable," he told reporters.
"People's consciousness has been raised on environmental issues and they will vote, no doubt, through the consumer choices they make."
Ignatius Jean, St Lucia's environment minister, said this amounted to a call for economic boycott, and labelled it "economic terrorism".
Speaking to the BBC from London, Mr Bradshaw said he was not calling for a boycott. "It is important that people in all countries, including developing countries, make up their own minds," he said.
The Caribbean nations are members of a 30-strong group which has tabled a "St Kitts Declaration" calling for the IWC to move towards a resumption of commercial whaling.
A vote on the declaration is anticipated at the end of Sunday's session.