More than 2,800 people have signed an online petition calling on Hong Kong Airlines to stop its live cargo business over allegations that dolphins were transported in "cruel confinement".

According to the AFP, the petition was started in January after the China Daily newspaper reported that five dolphins had been flown as cargo from Japan to Vietnam.

The dolphins are thought to have come from the Japanese town of Taiji, renowned for its annual dolphin hunt depicted in the Oscar-winning documentary 'The Cove'.

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"Five Taiji dolphins were transported via cargo flight in 'flying coffins' on January 16, 2012. They spent at least seven hours in this cruel confinement," the petition reads. "Dolphins are neither cargo, nor commerce, nor entertainment."

An internal memo to airline staff, reprinted by the China Daily, stated that the seven-hour flight had earned the airline HK$850,000 (US$110,000) in cargo revenue.

"The smooth handling of such special cargo which is time sensitive and vulnerable demonstrates that Hong Kong Airlines cargo handling capability has further improved," the memo said, adding: "Based on the experience we have obtained this time, Hong Kong Airlines cargo will develop the business onwards."

It included a photograph of the dolphins lying in shallow containers that the China Daily described as “coffin-shaped plastic funnels.”

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Other members of the online community have also condemned the airline's treatment of the dolphins, including the Animal Advocacy Examiner, which asked: 'Is Hong Kong Airlines benefitting from the misery of the Taiji dolphins?"

Hong Kong Airlines declined to comment on the recent media reports, but reportedly told the Sunday Morning Post newspaper that they were "fully committed to the protection of animal welfare" and wanted "open dialog" with animal welfare groups.

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