The death of a former head of China's one-child policy has been met not by tributes but by castigation of the abandoned policy on social media this week.

State media praised Peng Peiyun, head of China's Family Planning Commission from 1988 to 1998, as "an outstanding leader" in her work related to women and children.

The reaction on China's social media to Peng's death in Beijing on Sunday, just shy of her 96th birthday, was less positive.

"Those children who were lost, naked, are waiting for you over there" in the afterlife, one person posted on China's popular micro-blog Weibo.

China's near-universal mandate of just one child per couple from 1980 through 2015 prompted local officials to compel women to undergo abortions and sterilisations.

Beijing launched the one-child policy as leaders worried about population growth potentially spiralling out of control. But China's population, long the world's highest, later slowed and last year tumbled for the third year in a row.

"If the one-child policy had been implemented for 10 years less, China's population would not have plummeted like this!" a Weibo post said.

After falling behind India's in 2023, China's population declined last year to 1.39 billion. Experts warn the downtrend will accelerate in coming years. Data for 2025 will be released next month.

As population czar, Peng focused her commission's work on the countryside.

In rural China, large families were once seen as a goal for couples looking to ensure that they would be taken care of in their old age. Sons who could carry on the family name were also favoured, leading to unwanted infant girls and even aborted female foetuses.

"Those children, if they were born, would be almost 40 years old, in the prime of their lives," one person posted on Weibo.

By the 2010s, Peng had publicly shifted her views, saying the one-child policy should be eased. Now Beijing is trying to boost the flagging birth rate with childcare subsidies, longer maternity leave and tax benefits.

The shrinking and greying of the population has spurred worries that the world's second-biggest economy will struggle as the number of workers declines. Rising costs from elderly care and retirement benefits will also likely create additional budgetary strains for already indebted local governments.