WikiLeaks founder Julian Assange has been arrested at the Ecuadorian Embassy in London.
Scotland Yard says the 47-year-old Australian has been taken to a police station and will soon appear in court.
He reportedly yelled "the UK must resist" and fought to escape his captors before being bundled into a police van.
Assange claimed political asylum at the embassy since 2012, but British police say the Ecuadorian government withdrew asylum and invited them in.
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In a statement, WikiLeaks said Ecuador's decision to terminate his political asylum was "in violation of international law".
The group says Assange "did not walk out of the embassy", and allege that the Ecuadorian ambassador had actually invited British police in.
UK Home Secretary Sajid Javid says he can confirm that Julian Assange will face justice in the UK.
Meanwhile Scotland Yard issued a statement of its own, saying it had arrested Assange on a warrant issued in 2012 "for failing to surrender to the court".
"He has been taken into custody at a central London police station where he will remain, before being presented before Westminster Magistrates' Court as soon as is possible," the statement read.
"The MPS (Metropolitan Police Service) had a duty to execute the warrant, on behalf of Westminster Magistrates' Court, and was invited into the embassy by the Ambassador, following the Ecuadorian government’s withdrawal of asylum."
The latest development comes after WikiLeaks claimed Assange had been the subject of a sophisticated spying operation.
Assange's relations with his hosts chilled after Ecuador accused him of leaking information about President Lenin Moreno's personal life. Moreno claimed Assange had violated the terms of his asylum.
To some, Assange is a hero for exposing what supporters cast as abuse of power by modern states and for championing free speech. But to others, he is a dangerous rebel who has undermined the security of the United States.
Assange made international headlines in early 2010 when WikiLeaks published a classified US military video showing a 2007 attack by Apache helicopters that killed a dozen people in Baghdad, including two Reuters news staff.
Later that year, the group released over 90,000 secret documents detailing the US-led military campaign in Afghanistan, followed by almost 400,000 internal US military reports detailing operations in Iraq.
More than 250,000 classified cables from US embassies followed, then almost 3 million dating back to 1973.
Newshub / Reuters