Ai Weiwei installs studio webcams for supporters and security services

Outspoken Chinese artist Ai Weiwei is used to being the centre of attention. Now he is subject to more scrutiny than ever after installing four webcams in his studio, so admirers – and police – can watch him round the clock.

The 54-year-old artist said the live webfeed, installed one year after he was detained by officials, was a gift to supporters who worry for his safety and the public security bureau, who want to know what he has been up to.

"It is the exact day, one year ago, that I went missing for 81 days. All my family and friends and everyone who cared were wondering where this guy was. So on the anniversary I think people may have worries. It's a gift to them: I'm here and you can see me," he said.

His detention at Beijing airport , one of a spate of disappearances of activists last spring, caused an international outcry.

"This is also a gift to public security because they follow me, tap my phone and do what is necessary to get 'secrets' from me. I don't have secrets," Ai said, poiting out there were now 15 surveillance cameras within a 100m stretch of road outside his home, making it the most-watched area of Beijing.

"They want to watch me day and night. We have four cameras inside so they can see clearly what I am doing and make sure they are happy with it," he said. One of the cameras is mounted over his bed, one over his computer, another aimed at the studio and a fourth in his courtyard.

Ai said he had not decided how long they would remain in place. "I even forget they are there," he said. "If someone has a photo of me picking my nose, I'm not self-conscious. I'm just going to do my work and see what comes out."

Authorities say that Ai was detained for tax evasion and his case is unrelated to human rights. Last week, they told him he could not have a public hearing to reconsider a 15m yuan (£1.5m) tax fine allegedly owed by the company he works for.

Supporters say the case was politically motivated and it is hard to disprove the tax claims as police have confiscated the company's financial records and refuse to return them.

Ai has angered the authorities with his criticism, highlighting sensitive issues, particularly the death of children in poorly built schools during the 2008 earthquake in Sichuan.

Ai is living under bail conditions that require him to stay in Beijing for a year after his release.

He is co-designing this year's pavilion for the Serpentine Gallery in London, but it is not clear whether he will be able to attend the opening in June. "Every day I think, 'this will be the day I will be taken in again'," he said.

The cameras are the latest in a series of initiatives certain to rile officials. Previously, supporters tweeted nude pictures after officers suggested his cameraman was spreading pornography for taking a shot of Ai and four women, all naked.

Ai Weiwei's turbulent year

3 April 2011 China's best-known artist and outspoken critic of the regime is spirited away by police as he is about to board a plane for Hong Kong. He is accused of "economic crimes".

11 May Fears over the whereabouts of the artist grow as a planned exhibition of his work, Circle of Animals/Zodiac Heads, opens in London without him.

16 May Ai's wife is finally allowed to see her husband. Chinese authorities take her to an undisclosed location. Ai Weiwei is said to be in good health.

22 June International pressure on China leads to Ai's release. The Beijing police say they let him go "because of his good attitude in confessing his crimes". The artist is then handed a £1.5m tax bill.

7 November He raises £490,000 in public donations to help clear his tax bill. Supporters fold banknotes into paper planes, which they throw into his garden.

18 November Ai is investigated for spreading pornography after a photograph titled One Tiger Eight Breasts in which the artist posed with four women – all naked – is brought to the attention of the Chinese.

5 March 2012 The Tate buys 8m Ai Weiwei sunflower seeds, which represent a 10th of the number that covered the floor of Tate Modern's Turbine Hall in the hugely successful Sunflower Seeds exhibition of 2010.

3 April 2012 Ai decides to install webcams in his studio and turns them on on the anniversary of his detention. Jason Rodrigues