New evidence has revealed that an Apple iPhone was successfully hacked by a government user of NSO Group’s Pegasus spyware in December, weeks after the technology giant sued the Israeli company in a US court and called for it to be banned from “harming individuals” using Apple products.

A report published on Tuesday by security researchers at Front Line Defenders (FLD) and Citizen Lab at the University of Toronto found that phones belonging to four Jordanian human rights defenders, lawyers and journalists were hacked by government clients of NSO – which appear to be Jordanian government agencies – from August 2019 to December 2021.

The news appears to show that Apple users could still be vulnerable to surveillance by NSO’s government clients, even after the company sued NSO last November. At the time, Apple said it was filing suit against NSO and its parent company to “hold them accountable” for the “surveillance and targeting of Apple users”. It followed the identification of an exploit by Citizen Lab at the University of Toronto that allowed users of NSO to infect iPhones with the company’s Pegasus spyware through a vulnerability in its iMessage function. Apple said at the time that the vulnerability had been patched.

“The fact that the targeting we uncovered happened after the widespread publicity around Apple’s lawsuit and notifications to victims is especially remarkable; a firm that truly respected such concerns would have at least paused operations for government clients, like Jordan, that have a widely publicised track record of human rights concerns,” the report by FLD and Citizen Lab said.

Jordan’s National Center for Cyber Security “categorically denied” the findings of the report. “These allegations are baseless, and Jordan has not cooperated with any agents with the aim of spying on citizens’ phones or censoring their calls,” it told the Associated Press.

An NSO spokesperson had no comment on the findings, but said that the monitoring of dissidents, activists and journalist activists by any client would amount to a “severe misuse” of its product.

Once Pegasus is successfully deployed against a user, it can hack any phone, intercept messages and emails, view a user’s photographs and location, and turn the mobile into a remote listening device, allowing an NSO customer to listen in on conversation held in proximity to the phone.

NSO has said it investigates serious claims of abuse and that it does not know how its government clients use its spyware. It has said Pegasus is only meant to be used against serious criminals and terrorists.

Apple did not immediately respond to a request for comment.

The report by FLD and Citizen Lab named three Jordanians whose phones they said were hacked using Pegasus, including a human rights defender named Ahmed al-Neimat, who is currently in prison for a case related to protests at al-Salt state hospital, where lack of oxygen is alleged to have killed several Covid-19 patients.

The researchers found that human rights lawyer Malik Abu Orabi, who represents al-Neimat and other activists, was hacked at least 21 times between August 2019 and July 2021. A third target, Suhair Jaradat, is a human rights defender and journalist focused on women’s issues in the media. The researchers found that Jaradat had been sent text messages and WhatsApp messages with links to Pegasus spyware. The WhatsApp message, the researchers said, impersonated a popular anti-government Twitter user in Jordan.

The researchers’ findings were peer-reviewed and confirmed by Amnesty International’s security lab.

The latest news comes as NSO appears to be locked in battle with the managers of Berkeley Research Group, a consultancy that took over management of the fund that owns NSO last year. BRG is engaged in litigation in London with the previous owners of the fund, and claimed new details about its allegedly frayed relationship with NSO.

A witness statement filed by Finbarr O’Connor, the managing director of BRG in New York, alleged that cooperation from NSO’s management has been “virtually non-existent” since it began managing the fund that owns the Israeli company. O’Connor also said that BRG is “still not in possession of information” sufficient for it to understand “historic actions” by NSO that resulted in the Biden administration placing NSO on a commerce department blacklist.

NSO did not respond to questions about BRG’s claims. The allegations raise questions about corporate oversight of the company’s executive managers in the wake of last year’s publication of the Pegasus project, an investigation into NSO by Forbidden Stories, a journalistic collaboration that included the Guardian. The Pegasus project reported dozens of cases of individuals who were hacked or targeted by NSO’s government clients, including journalists, activists and government officials.

In O’Connor’s witness statement, the BRG executive said that he understood that NSO had undertaken efforts to identify potential US based investors early in 2021, but that the effort had been “halted as a result of the Pegasus Project”, which he said “negatively impacted investor interest”.

NSO did not respond to a request for comment in connection to that claim.

The company separately faced a new lawsuit in France by a French-Palestinian human rights defender named Salah Hammouri, who, with the International Federation of Human Rights and the Human Rights League, is suing NSO for violating privacy rights in France.

An investigation by FLD published in November found that the mobile phones of Hammouri, whose Jerusalem residency status has been revoked, and five other Palestinian human rights defenders were hacked using Pegasus, NSO’s signature spyware. FLD’s findings were independently confirmed with “high confidence” by technical experts at Citizen Lab and Amnesty International’s security lab, the world’s leading authorities on such hacks.

At the time, an NSO spokesperson said it could not confirm or deny the identity of government customers but that it does not operate products itself and is “not privy to the details of individuals monitored”.