Chinese artist Ai Weiwei warned not to attend his own court case Andy Wong / AP Ai Weiwei, second from left, stopped by a plain clothes policeman while he argues with another policeman, foreground, outside his home in Beijing on Wednesday. BEIJING - While Ai Weiwei didn't get his day in court Wednesday, he did get his case heard. The Chinese artist and social activist was noticeably absent from opening arguments at a Beijing courtroom after he was warned off by police. Instead, Ai, 54, stayed home at his studio while his wife, Lu Qing, represented their design company, Beijing Fake Cultural Development Ltd., with a team of lawyers. Ai and his wife are challenging a ruling by the tax office that rejected their appeal against a steep fine imposed for alleged tax evasion, a charge roundly rejected as false and trumped up by Ai and his supporters. NBC News spoke to Ai Weiwei by phone late Wednesday afternoon, but he could not comment on how legal proceedings had gone. The government previously ordered Ai's company to pay a staggering 15 million yuan ($2.4 million) in alleged back taxes and additional fines. Surprisingly, Ai raised the money needed to pay an 8.45 million yuan ($1.3 million) bond needed to contest the tax charges through donations and contributions from around 30,000 supporters after he called for assistance through social media, a favored tool of his and other activists in China. Stunts like these as well as his pokes at authority - see the photo he posted yesterday on Twitter sporting a too-tight Chinese police uniform - anger authorities who view Ai as a troublemaker. In April 2011, Ai was detained without charge during a national roundup of activists and dissidents following the many pro-democracy uprisings in the Middle East. It was only after his 81-day detention that tax-evasion charges against Ai and his company were made, lending credence to claims made by human rights watchers and Ai supporters that the move was retaliation by the government. The case against Ai has been shrouded in secrecy due to the government's unwillingness, or inability, to reveal any original tax documents as evidence of tax evasion they purport to have. Sharron Lovell / Polaris Click to see a slideshow of photos of projects done by the Chinese artist and activist Ai Wei Wei. A hearing held last July during which the government's evidence would ostensibly have been revealed was closed and the company's lawyers were barred from attending, a decision Ai's lawyers claim was illegal. It is a sensitive time politically in China as President Hu Jintao and Premier Wen Jiabao are poised to step down later this year. Despite the political drama swirling around the fleeing of dissident Chen Guangcheng to the United States and the ongoing Bo Xilai scandal, Beijing desperately wants to make the transition peaceful and is doing everything possible this year to mitigate sensitive stories. Yet, as has sometimes proven the case when it comes to Ai, attempts to muzzle or contain him can backfire. While Beijing police have discouraged local dissidents from going to the courthouse to support Ai, security was said to be intense around the court with a ring of police cars around it and officers telling foreign press to stay away as well. Still, supporters of Ai were seen outside holding small signs that said "Ai Weiwei, we love you" and "No justice without a fight." Meanwhile, the detention of Ai's legal consultant, Liu Xiaoyuan, by security forces Tuesday outraged Ai, who announced it on Twitter and called for Liu's immediate release. Ai told NBC News that Liu's phone had been turned off and that he had been "taken away to the countryside for some sort of treatment by the police." Additionally, Ai has also been using Twitter to call attention to the heavy police presence outside his home. He pointed to a bust up at his home yesterday when someone in his studio took a photo of what Ai described as "30-40 police cars." Ai alleges that police rushed the photographer to grab the camera, causing some minor scratches and bruises which were tweeted here. As part of his conditional release late last year, Ai's travel rights were taken away and he was told to refrain from criticism of the government through social media. Friday was supposed to be the day those restrictions would be lifted, but in lieu of Ai's continued defiance, it is hard to believe local authorities won't extend these restraints in order to rein him in.