A group of experts from around the world have criticized Japan's ongoing Antarctic Ocean whaling program as having no scientific basis in a letter published in British science journal Nature on Thursday.

The 32 signatories to the letter include 31 members of the International Whaling Commission's Scientific Committee and an independent expert witness who testified at an International Court of Justice hearing that resulted in a March 2014 ruling ordering Japan to suspend whaling in the Antarctic.

"In our view, the science behind Japan's whaling activity has not passed a reasonable standard of peer review," the letter states.

Japan's latest whaling plan, submitted to the IWC in December, provides for an annual catch of 333 minke whales, a reduction of about two-thirds from previous quotas, under the auspices of sampling the whale population.

The experts called for Japan to consider methods of sampling that do not require the whales to be killed.

They also urged reform in the IWC "to develop a process of scientific review that results in clear decisions that can be respected by all," calling the current process "a waste of time."

According to the letter, a review of Japan's latest proposal by an independent expert panel found a lack of justification for lethal sampling.

The experts said Japan claims to have taken the IWC Scientific Committee's opinions seriously but has failed to make changes to its proposal "in any meaningful way."