BEIJING — The Chinese artist and activist Ai Weiwei is often seen taking photos with his phone, and he frequently uploads selfies to social media sites.
But it appears that someone else has taken an interest in documenting Mr. Ai’s personal life. On Sunday, the artist, who had just returned from his first overseas trip in four years, said he had uncovered several listening devices hidden around his Beijing studio and living room.
A series of photos posted to the artist’s account on Instagram — which is banned in China but which people view through a virtual proxy network — showed various angles of a jumble of electric wires and what appeared to be a listening device hanging out of an electric outlet.
“Ai Weiwei came back to Beijing and came across some secrets from four years ago in the process of renovating the studio,” Liu Xiaoyuan, a human rights lawyer and Mr. Ai’s friend, wrote on his Twitter account. Mr. Ai spent more than two months abroad, visiting London, among other places in Europe, for the opening of his solo show at the Royal Academy of Arts.
Mr. Ai told CNN on Monday that the installation of the bugs appeared to have been a “professional job.”
“It only could be a job by gong an or guo an,” he said, referring to the police and to China’s state security bureau. The artist also said that he guessed that they had been there “for years,” or installed after his release from detention.
Surveillance has been a prominent theme in Mr. Ai’s work in recent years, particularly since he was put under house arrest in 2010 and detained by the Chinese government in 2011. He had been barred from traveling abroad since 2011, but the authorities returned his passport in July. The move appeared to be part of a broader decline in government pressure on the artist, who was also permitted to stage his first-ever show in mainland China this summer.
In April 2012, Mr. Ai set up a website called weiweicam.com, on which he streamed live video from several surveillance cameras set up in his home.
The artist has said in the past that making his life totally transparent through continuous documentation on social media was his response to the constant surveillance.
In a short video posted with the photos on Sunday, Mr. Ai gave a different kind of response: A person is seen setting off firecrackers in a bucket next to the recently discovered listening device. The caption reads: “Did you hear that?”