SYDNEY (REUTERS, BLOOMBERG) - Australia's Prime Minister Scott Morrison said on Monday (Nov 30) Canberra is seeking an apology from Beijing about a tweet containing a false image of an Australian soldier holding the knife to the throat of an Afghan child.

Mr Morrison said Australia was seeking the removal of the "truly repugnant" image posted on Monday by Mr Zhao Lijian, a spokesman at the Ministry of Foreign Affairs.

The prime minister said the image was doctored and called for Twitter to remove it.

"It is utterly outrageous and cannot be justified on any basis... The Chinese government should be utterly ashamed of this post. It diminishes them in the world's eyes," Mr Morrison told media at a press briefing.

He said countries around the world were watching how Beijing responded to tensions in Australia's relationship with China.

Mr Morrison's calls for an apology further ramps up tensions between the nations, following China's decision to impose crippling anti-dumping duties on its wine over the weekend.

Diplomatic ties have plummeted this year after Australia called for independent investigators to be allowed into Wuhan to probe the origin of the coronavirus pandemic, leading to a series of trade reprisals.

Mr Zhao's boss later dismissed Mr Morrison's demand for apology, asking at a briefing in Beijing whether the Australian leader "lacks a sense of right and wrong".

"It is the Australian government who should feel ashamed for their soldiers killing innocent Afghan civilians," said Ms Hua Chunying, China's foreign ministry spokesman, when asked about Mr Morrison's comments.

The image posted by her colleague shows people's indignation, said Ms Hua, speaking at a regular media briefing in Beijing on Monday. Whether it will be taken down is a matter between Twitter and the Australian government, she said.

Ms Hua added that it was the Australian side that should apologise to Afghanistan and she denied any link between the tweet and the broader dispute between China and Australia.

"That is totally unrelated with other issues between China and Australia - it's a matter of principle," Ms Hua said. "There are other issues between China and Australia, but the root cause for that is that Australia goes against basic norms of international relations and took wrong measures on issues bearing on China's core interests."

Australian special forces soldiers serving in Afghanistan were allegedly involved in 39 unlawful killings of prisoners, farmers and other civilians, a government-commissioned report found earlier this month.

Following a four-year inquiry, the report found there was credible information that 25 personnel may have been complicit and 36 matters should be referred to police for criminal investigation.

Mr Zhao, who has more than 175,000 followers on the social network banned in China, has a reputation for stirring diplomatic disputes with provocative Twitter posts.

In March, he floated a conspiracy theory that the US Army may have had a role in spreading the coronavirus in China, escalating a blame game in which President Donald Trump started referring to the disease as the "Chinese virus".

In his latest tweet, Mr Zhao said he was "shocked by murder of Afghan civilians & prisoners" by Australian soldiers. "We strongly condemn such acts, & call for holding them accountable," he said.

The tweet includes an image that purports to show a soldier standing on the Australian flag and holding a bloody knife to the throat of a child clutching a lamb. The child's face is covered with a blue cloth.

The text beneath the photo reads: "Don't be afraid, we are coming to bring you peace!"

Mr Zhao is closely associated with "Wolf Warrior" diplomacy, a more confrontational approach named after a nationalistic Chinese action film series of the same name.

The Wolf Warriors have come to the fore amid debates about China's early efforts to contain the coronavirus and policies to suppress human rights in places such as Hong Kong and the predominately Muslim region of Xinjiang.

Australia is the world's most China-dependent developed economy and finalised a free-trade agreement with Beijing in 2015.

Relations have been fraught since 2018, when Canberra barred Huawei Technologies from building its 5G network.

Ties went into free-fall earlier this year after Canberra's call for the virus probe, a move that bruised China's pride and unleashed a torrent of criticism that Australia is a puppet of the United States.

China has accused Australia of souring bilateral ties by interfering in its internal affairs, including criticism of Hong Kong's national security legislation and the internment of Uighurs, a Muslim ethnic group living in Xinjiang.

"There are undoubtedly tensions that exist between China and Australia, but this is not how you deal with them," Mr Morrison said of the tweet.