WIKILEAKS founder Julian Assange has been arrested at the Ecuadorian embassy in London.

Assange, 47, who has spent almost seven years at the embassy after seeking refuge there to avoid extradition to Sweden, was detained after the Ecuadorian government withdrew his asylum, Scotland Yard said.

WATCH: The moment Julian Assange is carried out of Ecuadorian Embassy

He was held on a warrant issued by Westminster Magistrates' Court on June 29, 2012 when he failed to surrender to the court.

Scotland Yard said: "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 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."

Assange has arrived at Westminster Magistrates' Court and is expected to appear before magistrates at 2pm, a court official confirmed.

Ahead of her statement on the latest  Brexit extension, Prime Minister  Theresa May​ welcomed the arrest of Julian Assange for breach of bail.

She told the Commons: "I'm sure the whole House will welcome the news this morning that the Metropolitan Police have arrested Julian Assange, arrested for breach of bail after nearly seven years in the Ecuadorian embassy.

"He has also been arrested in relation to an extradition request from the United States authorities.

"This is now a legal matter before the courts ... This goes to show that in the UK nobody is above the law."

Ecuador's president Lenin Moreno said on Twitter: "In a sovereign decision Ecuador withdrew the asylum status to Julian Assange after his repeated violations to international conventions and daily-life protocols."

But WikiLeaks said he had acted illegally in terminating Assange's political asylum "in violation of international law".

His arrest comes a day after Wikileaks accused the Ecuadorean government of an "extensive spying operation" against Assange.

WikiLeaks claims meetings with lawyers and a doctor inside the embassy over the past year were secretly filmed.

Assange had refused to leave the embassy, claiming he would be extradited to the United States for questioning over the activities of WikiLeaks if he did so.

Home Secretary Sajid Javid tweeted: "Nearly 7yrs after entering the Ecuadorean Embassy, I can confirm Julian Assange is now in police custody and rightly facing justice in the UK. I would like to thank Ecuador for its cooperation & @metpoliceuk for its professionalism. No one is above the law."

WikiLeaks tweeted: "URGENT: Ecuador has illigally (sic) terminated Assange political asylum in violation of international law. He was arrested by the British police inside the Ecuadorian embassy minutes ago."

Ecuador's president Lenin Moreno said on Twitter: "In a sovereign decision Ecuador withdrew the asylum status to Julian Assange after his repeated violations to international conventions and daily-life protocols."

Europe and the Americas minister Sir Alan Duncan said: "It is absolutely right that Assange will face justice in the proper way in the UK. It is for the courts to decide what happens next.

"We are very grateful to the government of Ecuador under President Moreno for the action they have taken.

"Today's events follow extensive dialogue between our two countries. I look forward to a strong bilateral relationship between the UK and Ecuador in the years ahead."

Two armed officers went into the building on Saturday and people taking part in a vigil said teams of plain clothes officers were outside the embassy throughout the weekend.

A number of surveillance cameras have been positioned opposite the embassy.

Assange was shouting and gesticulating as he was carried out of the Ecuadorian Embassy in handcuffs by seven men and put into a waiting Met Police van, video footage showed.

He appeared to be carrying a book.

Sources said that police were invited into the embassy and made the arrest shortly after 10am.

The Swedish woman who alleged that she was raped by Julian Assange during a visit to Stockholm in 2010 welcomed his arrest.

Elisabeth Massi Fritz, who represents the unnamed woman, said news of Assange's arrest was "a shock to my client" and something "we have been waiting and hoping for since 2012".

Ms Massi Fritz said in a text message sent to the Associated Press that "we are going to do everything" to have the Swedish case reopened "so Assange can be extradited to Sweden and prosecuted for rape".

She added that "no rape victim should have to wait nine years to see justice be served".

WikiLeaks said Assange had been arrested under a US extradition warrant for conspiracy with Chelsea Manning for publishing classified information revealing war crimes in 2010.

WikiLeaks revealed last year there was a sealed indictment for his arrest in the US and has been pressing for an assurance from the UK Government that he would not be sent to the US if he left the building.

Jeremy Hunt tweeted: "Julian Assange is no hero and no one is above the law. He has hidden from the truth for years.

"Thank you Ecuador and President Lenin Moreno for your cooperation with the Foreign Office to ensure Assange faces justice."

Supporters of Assange reported increased police activity at the embassy last weekend.