The Chinese social media platform WeChat blocked a message by Australia Prime Minister Scott Morrison amid a dispute between Canberra and Beijing over the doctored tweeted image of an Australian soldier.
China rebuffed Morrison's calls for an apology after its foreign ministry spokesman Zhao Lijian posted the picture of an Australian soldier holding a bloodied knife to the throat of an Afghan child on Monday.
The United States called China's use of the digitally manipulated image a "new low" in disinformation.
Morrison took to WeChat on Tuesday to criticise the "false image", while offering praise to Australia's Chinese community.
In his message, Morrison defended Australia's handling of a war crimes investigation into the actions of special forces in Afghanistan, and said Australia would deal with "thorny issues" in a transparent manner.
But that message appeared to be blocked by Wednesday evening, with a note appearing from the "Weixin Official Accounts Platform Operation Center" saying the content was unable to be viewed because it violated regulations, including distorting historical events and confusing the public.
Tencent, the parent company of WeChat, did not immediately respond to a request for comment.
Australian special forces allegedly killed 39 unarmed prisoners and civilians in Afghanistan, with senior commandos reportedly forcing junior soldiers to kill defenceless captives in order to "blood" them for combat, a four-year investigation found.
Australia said last week that 19 current and former soldiers would be referred for potential criminal prosecution.
China's embassy has said the "rage and roar" from Australian politicians and media over the soldier image was an overreaction.
'HYPOCRISY IS OBVIOUS TO ALL'
Australia was seeking to "deflect public attention from the horrible atrocities by certain Australian soldiers", it said.
Other nations, including the United States, New Zealand and France - and the self-ruled island of Taiwan which China claims as its own - have expressed concern at the Chinese foreign ministry's use of the manipulated image on an official Twitter account.
"The CCP's latest attack on Australia is another example of its unchecked use of disinformation and coercive diplomacy. Its hypocrisy is obvious to all," the U.S. State Department said on Wednesday, referring to the Chinese Communist Party.
State Department deputy spokesman Cale Brown said the fabricated image of the soldier was "a new low, even for the Chinese Communist Party".
"As the CCP spreads disinformation, it covers up its horrendous human rights abuses, including the detention of more than a million Muslims in Xinjiang," Brown wrote in a tweet.
France's foreign affairs spokesman said on Tuesday the tweeted image was "especially shocking" and the comments by Zhao "insulting for all countries whose armed forces are currently engaged in Afghanistan".
China's embassy in Paris hit back on Wednesday, saying the soldier image was a caricature by a painter, adding that France has previously loudly defended the right to caricature.
WeChat has 690,000 active daily users in Australia, and in September told an Australian government inquiry it would prevent foreign interference in Australian public debate through its platform.
Morrison's message had been read by 57,000 WeChat users by Wednesday.
Zhao's tweet, pinned to the top of his Twitter account, had been "liked" by 60,000 followers after Twitter labelled it as sensitive content but declined Canberra's request to remove the image.
Twitter is blocked in China but has been used by Chinese diplomats.
China on Friday imposed dumping tariffs of up to 200% on Australian wine imports, effectively shutting off the largest export market for the Australian wine industry.
A group of parliamentarians from 19 countries that has lobbied against China's actions in Hong Kong, where it has cracked down on dissent, and in the farwestern region of Xinjiang campaigned on social media for the public to drink Australian wine.