Amid the varied cast of people whose numbers appear on a list of individuals selected by NSO Group’s client governments, one name stands out as particularly ironic. Pavel Durov, the enigmatic Russian-born tech billionaire who has built his reputation on creating an unhackable messaging app, finds his own number on the list, The Guardian reports.

Durov, 36, is the founder of Telegram, which claims to have more than half a billion users. Telegram offers end-to-end encrypted messaging and users can also set up “channels” to disseminate information quickly to followers. It has found popularity among those keen to evade the snooping eyes of governments, whether they be criminals, terrorists or protesters battling authoritarian regimes.

In recent years, Durov has publicly rubbished the security standards of competitors, particularly WhatsApp, which he has claimed is “dangerous” to use. By contrast, he has positioned Telegram as a plucky upstart determined to safeguard the privacy of its users at all costs.

Without a forensic examination of Durov’s phone, it is not possible to say whether there was any attempt to install malware on the device.

An NSO source indicated Durov was not a target, meaning the source denies he was selected for surveillance using Pegasus, NSO’s spyware. The company insists that the the fact that a number appeared on the list was in no way indicative of whether that number was selected for surveillance using Pegasus.

Asked directly whether Durov’s phone was a target of Pegasus or any other activity related to the spyware, an NSO spokesperson did not directly answer the question. They said: “Any claim that a name in the list is necessarily related to a Pegasus target or potential target is erroneous and false.” Lawyers for NSO said its decision not to respond to certain allegations should not be treated as confirmation of those claims.