A network of more than 700 fake social media accounts has sprung up in the last week of Germany's election campaign, researchers say, promoting pro-Russian narratives and demonising conservative election frontrunner Friedrich Merz.

Friedrich Merz, who is poised to become Germany's chancellor in a CDU-led government, has extensive experience as a lawyer and working with major corporations.

German nationals are heading to the ballots on February 23, with the country's current Chancellor, Olaf Scholz, down in opinion polls. The leader's centre-left Social Democrats (SPD) are trailing in third place, with the far-right Alternative for Germany (AfD) ahead of his party in second.