Following Assange's arrest on 11 April 2019, the case was reopened under prosecutor Eva-Marie Persson. On 19 November, she announced that she had discontinued her investigation, saying that the evidence was not strong enough. She added that although she was confident in the complainant, "the evidence has weakened considerably due to the long period of time that has elapsed".
In February 2019, the parliament of Geneva passed a motion demanding that the Swiss government extend asylum to Assange. In January 2020, the Catalan Dignity Commission awarded Assange its 2019 Dignity Prize for supporting the Catalan people during the 2017 Catalan independence referendum.
Assange submitted a complaint to the Inter-American Commission on Human Rights and accused the Ecuadorian embassy of monitoring his daily activities and restricting his visitors. The complaint requested the Ecuadorian government to "ease the conditions that it had imposed on his residence" at the embassy. Furthermore, the complaint urged the commission to forbid the embassy from extraditing him to the US. In March 2019, the commission rejected his complaint.
On 2 April 2019, Ecuador's president Moreno said that Assange had violated the terms of his asylum, after photos surfaced on the internet linking Moreno to a corruption scandal. WikiLeaks said it had acquired none of the published material, and that it merely reported on a corruption investigation against Moreno by Ecuador's legislature. WikiLeaks reported a source within the Ecuadorian government saying that, due to the controversy, an agreement had been reached to expel Assange from the embassy and place him in the custody of UK police. According to critics of Moreno, such as former Ecuadorian foreign minister Guillaume Long, the revoking of Assange's asylum was connected to an upcoming decision by the International Monetary Fund to grant Ecuador a $4.2 billion loan.
On 11 April 2019, the Metropolitan Police were invited into the embassy and arrested Assange in connection with his failure to surrender to the court in June 2012 for extradition to Sweden. Moreno stated that Ecuador withdrew Assange's asylum after he repeatedly violated international conventions regarding domestic interference. Moreno referred to Assange as a "spoiled brat" and "miserable hacker". British foreign secretary Jeremy Hunt thanked Moreno for co-operation, and the British prime minister, Theresa May, said that "no one is above the law". The Australian prime minister, Scott Morrison, said that Assange is "not going to be given special treatment ... It has got nothing to do with [Australia], it is a matter for the US".
Assange was remanded to HM Prison Belmarsh, and on 1 May 2019 he was sentenced to 50 weeks imprisonment. The judge said he would be released after serving half of his sentence, subject to other proceedings and conditioned upon committing no further offences. The United Nations Working Group on Arbitrary Detention said that the verdict contravened "principles of necessity and proportionality" for what it considered a "minor violation". Assange appealed his sentence, but dropped his appeal in July.
On 10 April 2019, WikiLeaks said it had uncovered an extensive surveillance operation against Assange from within the embassy. WikiLeaks said that "material including video, audio, copies of private legal documents and a medical report" had surfaced in Spain and that unnamed individuals in Madrid had made an extortion attempt.
On 26 September 2019, the Spanish newspaper El País reported that the Spanish defence and security company Undercover Global S.L. (UC Global) had spied on Assange for the CIA during his time in the embassy. UC Global had been contracted to protect the embassy during this time. According to the report UC Global's owner David Morales had provided the CIA with audio and video of meetings Assange held with his lawyers and colleagues. Morales also arranged for the US to have direct access to the stream from video cameras installed in the embassy at the beginning of December 2017. The evidence was part of a secret investigation by Spain's High Court, the Audiencia Nacional, into Morales and his relationship with US intelligence. The investigation was precipitated by a complaint by Assange that accused UC Global of violating his privacy and client-attorney privileges as well as committing misappropriation, bribery and money laundering.
In February 2019, Chelsea Manning was subpoenaed to appear before a grand jury in Virginia in the case. When Manning condemned the secrecy of the hearings and refused to testify, she was jailed for contempt of court on 8 March 2019. On 16 May 2019, Manning refused to testify before a new grand jury investigating Assange, stating that she "believe[d] this grand jury seeks to undermine the integrity of public discourse with the aim of punishing those who expose any serious, ongoing, and systemic abuses of power by this government". She was returned to jail for the 18-month term of the grand jury with financial penalties.
On 11 April 2019, the day of Assange's arrest in London, the indictment against him was unsealed. He was charged with conspiracy to commit computer intrusion (i.e. hacking into a government computer), which carries a maximum 5-year sentence. The charges stem from the allegation that Assange attempted and failed to crack a password hash so that Chelsea Manning could use a different username to download classified documents and avoid detection. This information had been known since 2011 and was a component of Manning's trial; the indictment did not reveal any new information about Assange.
On 23 May 2019, Assange was indicted on 17 new charges relating to the Espionage Act of 1917 in the United States District Court for the Eastern District of Virginia. These charges carried a maximum sentence of 170 years in prison. The Obama administration had debated charging Assange under the Espionage Act, but decided against it out of fear that it would have a negative effect on investigative journalism and could be unconstitutional. The New York Times commented that it and other news organisations obtained the same documents as WikiLeaks also without government authorisation. It said it was not clear how WikiLeaks's publications were legally different from other publications of classified information.
Since his arrest on 11 April 2019, Assange has been incarcerated in HM Prison Belmarsh in London.
After examining Assange on 9 May 2019, the United Nations special rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, Nils Melzer, concluded that "in addition to physical ailments, Mr Assange showed all symptoms typical for prolonged exposure to psychological torture, including extreme stress, chronic anxiety and intense psychological trauma." The British government said it supported the important work of the rapporteur's mandate but disagreed with some of his observations. In a later interview, Melzer criticised the "secretive grand jury indictment in the United States", the "abusive manner in which Swedish prosecutors disseminated, re-cycled and perpetuated their 'preliminary investigation' into alleged sexual offences", the "termination by Ecuador of Mr Assange's asylum status and citizenship without any form of due process", and the "overt bias against Mr Assange being shown by British judges since his arrest". He said the United States, UK, Sweden and Ecuador were trying to make an example of Assange. He also accused journalists of "spreading abusive and deliberately distorted narratives". Shortly after Melzer's visit, Assange was transferred to the prison's health care unit.
On 1 November 2019, Melzer said that Assange's health had continued to deteriorate and his life was now at risk. He said that the UK government had not acted on the issue.
On 30 December 2019, Melzer accused the UK government of torturing Julian Assange. He said Assange's "continued exposure to severe mental and emotional suffering ... clearly amounts to psychological torture or other cruel, inhuman or degrading treatment or punishment."
On 2 May 2019, the first hearing was held in London into the U.S. request for Assange's extradition. When asked by Judge Snow whether he consented to extradition, Assange replied, "I do not wish to surrender myself for extradition for doing journalism that has won many, many awards and protected many people". On 13 June, British Home Secretary Sajid Javid said he had signed the extradition order.
On 21 October 2019, Assange appeared at the court for a case management hearing. When Judge Baraitser asked about his understanding of the proceedings, Assange replied: