A Chinese province has asked residents to blow the whistle on neighbours they suspect of being cryptocurrency miners, in a new sign of how authorities in the country are cracking down on the booming industry.

The Inner Mongolia Development and Reform Commission said that it would set up a telephone hotline through which people could report suspected mining outfits as part of an effort to “comprehensively clean up and shut down” these operations.

The development comes as concerns grow over a crackdown on bitcoin and other digital currencies in the world’s second-biggest economy. A warning from China’s central bank this week that they were “not real currencies” and that financial institutions should avoid using them was followed by a plunge of as much a 30 per cent in the price of bitcoin.