Chinese police detained several dozen Chinese investors who lost money in the collapse of a metals trading scheme before they could participate in a protest in Beijing yesterday, amid a crackdown on dissent.

While investors in the Fanya Metals Exchange were able to stage a sit-in in front of the country’s top securities regulator last month, yesterday’s protest, timed to coincide with the start of a key meeting of China’s Communist party central committee, seems to have been judged a step too far during a sensitive political conference.

Many investors lost considerable savings in the exchange collapse which, in the wake of the summer’s domestic stock market crash, serves as an uncomfortable reminder to Chinese authorities of how financial turmoil can lead to social unrest.