TOKYO — A Japanese court on Tuesday rejected an appeal by two Greenpeace activists sentenced to suspended one-year jail terms for stealing a box of whale meat as part of an investigation.

Junichi Sato and Toru Suzuki were convicted of theft and trespass last September by the Aomori district court for illegally taking a 23-kilogramme (50-pound) box filled with whale meat in 2008.

The environmental activists contend that they acted in the public interest by exposing embezzlement in the state-funded whaling programme, which Japan says it carries out for scientific research.

They admitted to entering a truck depot and stealing the salted whale meat, which was destined for the home of a whaling crew member, but appealed the sentence against them, saying they were exposing graft.

The Sendai High Court rejected the appeal, an official told AFP.

Ahead of the ruling, Sato said in video footage: "This is a trial concerning people's right to know and freedom of expression. If the people's right to know is upheld, it will be useful for Japan to build a democratic society."

"The government can no longer ignore the embezzlement we exposed," Sato, now the Greenpeace Japan executive director, added in a statement, referring to claims some whalers secretly trade in whale meat.

"It must fully investigate the whale meat scandal, finally end its support for the expensive, unwanted and unneeded whaling programme, and put the money wasted on it into recovering from the March 11 disaster."

Commercial whaling was banned worldwide in 1986, but Japan has since culled hundreds of the ocean mammals annually in the name of science.

Japan has repeatedly clashed with activists over the hunting of both whales and dolphins -- including in annual high-seas confrontations with another environmental group, the US-based Sea Shepherd Conservation Society.

In July last year, a Sea Shepherd activist, New Zealander Peter Bethune, received a suspended two-year jail term over clashes with whalers in Antarctic waters in which he scaled a harpoon ship. He was deported after the sentence.

Dolphin hunting, which many Japanese defend as a tradition, has also brought activists to Japan after the Oscar-winning eco-documentary "The Cove" shone a spotlight on the annual slaughter in the coastal town of Taiji.