Dissident Chinese artist Ai Weiwei has posted photos on his Instagram account that suggest listening devices were planted in his Beijing studio.

The photos, which were posted on Sunday on the image-sharing social network, include pictures of wires pulled out from a wall socket and another device with about a dozen wires protruding from it.

"There will always be surprises," read a comment Ai posted with the latter picture.

Lawyer Liu Xiaoyuan said that Ai found the devices after coming back to China from Europe.

"Ai Weiwei returned to Beijing and unexpectedly discovered a four-year-old secret when decorating his studio," Liu wrote in a post on Twitter, apparently referring to the artist's detention in 2011 for 81 days.

Following the 2011 detention, Ai was subsequently placed under house arrest and had his passport taken away. The document was only returned in July this year, enabling him to travel to Europe.

Ai helped design the 2008 Beijing Olympics Bird's Nest Stadium and has staged art shows around the world.

But he has also run afoul of the Chinese government over his advocacy of democracy and human rights as well as other criticisms, including the aftermath of the deadly Sichuan earthquake in 2008.

In 2009 Ai was beaten by security officials, an incident believed to have caused a cerebral haemorrhage for which he later underwent brain surgery in Germany.

A major retrospective of Ai's work opened last month at London's Royal Academy of Arts.