An acting mayor in China who reportedly aired warnings that women from a local minority group used witchcraft to ensnare men is being investigated for making insulting remarks.

Top official Gong Qing sparked an outcry with comments he allegedly made at a meeting held to discuss plans for a new cultural park in the south-western Yunnan province that would celebrate the Miao ethnic group.

Mr Gong apparently veered from the seemingly positive agenda to highlight concerns about the minority, which is known in China for being superstitious.

"The witchcraft culture of the Miao minority is scary," Mr Gong said, according to an anonymous letter released on social media which detailed the contents of the discussions.

"When I first started to work here, someone told me to never attempt to get too near a girl from the Miao minority. If you did, you will never be able to get rid of her witchcraft. What is the value in publicising such a culture?"

The Miao, which is one of 56 minority groups in China, number about nine million people and live mainly in mountains across the country’s southern and central areas.