New analysis of a coordinated misinformation campaign targeting Hong Kong protesters suggests the Chinese government has been running covert online operations for years, using spam accounts to target a range of political opponents.

A report from the Australian Strategic Policy Institute sheds light on the "significant state-backed information operation" disclosed last month by Twitter and Facebook, involving thousands of accounts in an alleged effort to undermine the protest movement.

Misinformation campaigns on Twitter may have been going for years longer than previously thought. Credit:Reuters

Research by ASPI's International Cyber Policy Centre, based on data released by Twitter, found "actors linked to the Chinese government may have been running covert information operations on Western social media platforms for at least two years".

According to the report, accounts used in the effort previously focused on other targets of the Chinese Communist Party, including exiled businessman Guo Wengui and Hong Kong publisher Gui Minhai. The accounts were then active in a small and "hastily assembled" operation targeting this year's protests.