More than 100 websites disguised as local news outlets in Europe, Asia and Latin America are pushing pro-China content in a widespread influence campaign linked to a Beijing public relations firm, digital watchdog Citizen Lab has found.

Spread over websites in 30 countries, the propaganda material is interspersed with news aggregated from local news outlets and Chinese state media, according to a research report the Toronto-based group released on Wednesday.

"While the campaign's websites enjoyed negligible exposure to date, there is a heightened risk of inadvertent amplification by the local media and target audiences, as a result of the quick multiplication of these websites and their adaptiveness to local languages and content," researcher Alberto Fittarelli said in the report.