UK police say they were invited into the Ecuadorian embassy after its government withdrew asylum.
Assange was taken into custody at a central London police station, before he’s presented at Westminster Magistrates’ Court.
The United States Justice Department has filed criminal charges against Assange, 47, related to the publication of classified documents, a fact that prosecutors accidentally made public in November. He also faces a charge in a British court of jumping bail.
Assange is also suspected of aiding Russian interference in the 2016 presidential election by releasing material stolen from the computers of the Clinton campaign and the Democratic Party. In July, the Justice Department charged 12 Russian intelligence officers with hacking those computers, and the indictment contends that at least one of them was in contact with WikiLeaks.
Julian Assange has been the subject of a sophisticated spying operation in the Ecuadorean embassy where he has been holed up since 2012, the group said.
Assange’s future in the embassy was called into question last year after the president of Ecuador said he would “eventually” have to leave the property and revealed that he was in discussions with British authorities to end his asylum.
The WikiLeaks founder was first granted asylum in 2012 in order to avoid extradition to Sweden over allegations of sexual assault.
The lawyer also said Assange had also told her to pass a message to his supporters that his repeated warnings about the risk of US extradition had been proved right.