Ai Weiwei has found what appear to be “listening devices or ‘bugs'” hidden at his home in Beijing.

The influential and controversial Chinese artist Weiwei posted a video and image to Instagram showing a “listening device” hidden behind a socket in the wall. “It only could be a job by gong an (public security bureau) or guo an (national security), which, I wouldn’t know,” the artist and dissident told CNN. “Even though I was quite sure that these technologies have existed and the authorities have been using them […] it has been there, so close to me and for an unknown length of time.”

Critical opinions and other forms of protest against the Chinese government , predominantly through his art, has gained the attention of the Chinese government for some time.

Weiwei has paid the price for his charged outbursts – that were predominantly staged via Sina Weibo and Twitter – and was subsequently detained in 2011 on allegations of tax evasion. A year before that he was placed under house arrest. He claims the allegations of evasion were politically motivated in order to silence him (they’d be lucky).

The Royal Academy is currently exhibiting Ai Weiwei’s work in a retrospective spanning two decades of his career. Most significant in the exhibition is the artist’s Tree series, which began in 2009. Crowd-funding platforms helped to facilitate the transportation, configuration and re-building of the trees to make the exhibition a comprehensive snapshot of the artist’s impact on the art world.

Ai Weiwei’s self-titled exhibition runs until 13th December at the Royal Academy, London