German security services believe a Russia-linked group was behind a fake video recently spread online alleging plans for Chancellor Friedrich Merz's resignation, a source there told AFP Friday.

The video uses the branding of German public broadcaster Deutsche Welle and business daily Handelsblatt to claim that leaked documents from Merz's conservative CDU party showed he was planning to resign next week in reaction to his poor poll ratings.

Both media organisations have said the video is a complete fabrication.

Merz's office told AFP in a statement that the video's claims were "completely invented" and aimed at "confusing and unnerving people". His CDU party dismissed it as "nonsense".

A security source told AFP that the "creator is probably Storm 1516", an operation linked to Russian military intelligence.