Ai Weiwei 'finds bugging devices' at his Beijing studio

Ai Weiwei has returned to Beijing after a trip to Germany

Ai Weiwei has posted a number of pictures of what he says are listening devices found in his Beijing studio.

The Chinese dissident artist captioned one photo of a bug on Instagram with "There will always be surprises".

His friend Liu Xiaoyuan confirmed the bugs were found after the artist returned from a trip to Germany.

Xiaoyuan tweeted that they were found when redecoration started on Ai's home and were found in the office and a living room.

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The pictures show the devices were hidden in electric sockets.

The artist also posted a video clip of firecrackers being set off in a metal bucket next to one of the devices. He wrote "Did you hear it?" next to the video.

This Instagram photo shows a listening device behind a plug socket in a wall

'There will always be surprises' was Ai Weiwei's caption to this photo

The artist has retweeted an article saying listening devices had been found at his studio.

His mother Gao Ying told Radio Free Asia that she believed the devices were placed in his studio four years ago when the artist was arrested and his studio was searched by the authorities.

The artist has long been critical of the ruling Communist Party and was held in 2011 for 81 days before being released.

He was arrested during a government crackdown on political activists. He was held over alleged crimes of bigamy and tax evasion, but was released without charge.

He was later given a 15 million yuan (£1.5m) fine for evading taxes, although the artist maintains the charges were politically motivated in retaliation for his criticism of the Chinese Government.

The authorities kept his passport for four years but it was returned earlier this year.

Since then he has visited Germany, where his son lives, and London.

In September he was in London for the launch of a retrospective of his work at the Royal Academy.