Chinese artist Ai Weiwei said Tuesday he had set up four live webcams in his home in a symbolic reference to the 24-hour police surveillance he has been subjected to since his detention a year ago. Ai -- whose activism has made him a long-standing thorn in the side of Chinese authorities -- disappeared into custody on April 3 last year as police rounded up dissidents amid online calls for Arab-style protests in China. He was eventually released in June, but was given a one-year probation during which he cannot leave Beijing, and has been subjected to constant police surveillance. "In my life, there is so much surveillance and monitoring -- my phone, my computer... Our office has been searched, I have been searched, every day I am being followed, there are surveillance cameras in front of my house," he said. "So I was wondering, why don't I put some (cameras) in there so people can see all my activities. I can do that and I hope the other party (authorities) can also show some transparency," he told AFP. When he was released, the 54-year-old was charged with tax evasion linked to Fake Cultural Development Ltd -- a company founded by Ai but owned by his wife. But he has denied the charge and insists it is an attempt to silence his activism. Lawyers for the firm have also pointed out inconsistencies in the case. "Until now, there have been no clear answers as to why they put me in this kind of situation," he said. The webcams project includes a camera set up over his bed and one at his desk, and can be accessed on http://weiweicam.com. The artist has previously angered authorities with his investigation into the collapse of schools in the 2008 Sichuan earthquake and into a 2010 fire at a Shanghai high-rise that killed dozens. His art work has sold worldwide and he was named the world's most powerful art figure by influential British magazine Art Review last year. Ai said he was "doing OK" a year after his detention, adding he had regained all the weight he lost in detention and was preparing an exhibition due to take place in Washington DC in the autumn. His one-year probation, meanwhile, is expected to end on June 22. On that day, "I'm supposed to be a free man, unless they accuse me again and put me in jail. Otherwise, I should be free. But I don't know, it's never really clear," he said.