The Ecuadorian government has been accused of an “extensive spying operation” against Wikileaks founder Julian Assange which has led to a police investigation into claims of extortion.

Meetings with lawyers and a doctor inside the Ecuador embassy in London over the past year have been secretly filmed, Wikileaks said.

The anti-secrecy organisation said it had been offered all the material from an unnamed person in Spain, if it paid €3m.