"I want to leave and be with my husband," read the handwritten sign, held up to the camera and posted on Twitter in the early hours of Tuesday morning.
Its author - Nadila Wumaier, a member of China's Uighur Muslim minority - is reportedly under house arrest in China's western Xinjiang region with her two-year-old son.
She wanted her message to be known, after a Chinese official went on Australian television and told audiences Ms Wumaier was in China by choice.
Her husband, Sadam Abdusalam, had challenged the claim during the same programme - ABC's Q&A news - on Monday evening.
Mr Abdusalam has been campaigning for his wife's release for months.
Although Ms Wumaier is not an Australian citizen, both her husband and son Lutfy are, and the Australian government has previously formally requested that they be allowed to leave China.
"My son is an Australian citizen and holding an Australian passport and I have never met him," said Mr Abdusalam, during the broadcast.
"The Australian Government have given my wife a visa so they can come and join me in Australia, but the Chinese Government won't let them leave," he went on to say. "Why have the Communist Party locked up one million Uighurs? Will you release our family members?"
Rights groups say China is holding about a million Uighurs and other Muslims in detention. However, China denies any wrongdoing, saying it is combating terrorism and religious extremism.
In Ms Wumaier's case, Chinese authorities have been tight-lipped.
However, Wang Xining, the deputy head of mission at the Chinese embassy in Australia, made a rare public appearance as a guest on Q&A.
He responded to criticism by saying that the couple's marriage was not recognised under Chinese law and that Ms Wumaier had expressed a wish to remain in China.
Some hours after the broadcast, Mr Abdusalam shared his wife's handwritten denial via his Twitter account.
Last night on @QandA the Chinese embassy official lied and said my wife and son did not want to be with me. Here is the proof this not true. Here she is today with my son Lutfy I have never even met. Let them leave! Let me be with my family! #Uyghurs #Xinjiang pic.twitter.com/4k5uwuMypo— sadam_abdusalam (@SMusapir) February 25, 2020
Amnesty International Australia rejected Mr Wang's statement, saying that both Ms Wumaier and the partner of another Uighur Australian held in Xinjiang were "desperate to [be] reunited in Australia".
China is facing growing criticism over its persecution of Uighur Muslims.
A document seen recently by the BBC appears to give the most powerful insight yet into how China determined the fate of hundreds of thousands of Muslims held in the camps.