The news that Julian Assange had been arrested in the Ecuadorian Embassy was greeted with cheers in the House of Commons.
Theresa May welcomed the news ahead of her statement to MPs on the Brexit extension agreed late last night.
She told MPs Assange's arrest showed that "in the UK, nobody is above the law."
The Wikileaks founder was arrested this morning after police were invited into the Ecuadorian Embassy, where he has been living for seven years.
Mrs May said: "I am sure that the whole house will welcome the news this morning that the Metropolitan Police has arrested Julian Assange."
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She went on: "Arrested for breach of bail after seven years in the Ecuadorian Embassy.
"He has also been arrested in relation to an extradition request by the United States authorities.
"This is now a legal matter before the courts.
"My right honourable friend the Home Secretary will make a statement on this later.
"But I would like to thank the Metropolitan Police for carrying out their duties with great professionalism and to welcome the cooperation of the Ecuadorian government in bringing this matter to a resolution.
"Mr Speaker, this goes to show this goes to show that nobody is above the law."
Julian Assange's shocking appearance as he's arrested after 7 years in hiding
Home Secretary Sajid Javid will give a statement to the House on the arrest later this afternoon.
In a statement released following the arrest, Foreign Secretary Jeremy Hunt said: "What we’ve shown today is that no one is above the law. Julian Assange is no hero. He has hidden from the truth for years and years and it is right that his future should be decided in the British judicial system.
"What’s happened today is the result of years of careful diplomacy by the Foreign Office and I commend particularly our ambassador in Ecuador and Sir Alan Duncan and his team here in London for their work.
"But it is also a very courageous decision from President Moreno in Ecuador to resolve this situation that has been going on for nearly seven years.
"I mean it’s not so much Julian Assange being held hostage in the Ecuadorian Embassy, it’s actually Julian Assange holding the Ecuadorian Embassy hostage in a situation that was absolutely intolerable for them.
"So this will now be decided properly, independently by the British legal system respected throughout the world for its independence and integrity and that is the right outcome.
“We have been talking to Ecuador for a very long time about how to resolve this situation. We are a law-abiding country and we will always uphold the law so we have to follow all the international rules in a situation like this.
"But there was a change of leadership in Ecuador. President Moreno took a courageous decision which has meant we were able to resolve the situation today.
"We’re not making any judgement about Julian Assange’s innocence or guilt, that is for the courts to decide. But what is not acceptable is for someone to escape facing justice and he has tried to do that for a very long time and that is why he is no hero.”
