Dissident Chinese artist Ai Weiwei was in two places at once on Wednesday night. In Beijing, barred from leaving the country, and in the leafy London borough of Hampstead – on stage.

Such a breaking of boundaries has come to define Ai. The sculptor, photographer and installation artist is famed for filling London’s Tate Modern with porcelain seeds and as a consultant on China’s National ‘Bird’s Nest’ Stadium. But he has also snapped his wife flashing her knickers in Tiananmen Square.

The world premiere of #aiww: The Arrest of Ai Weiwei, which opened to a packed Hampstead theatre, addresses the artist’s clash with Chinese authority over freedom of expression. The title’s hashtag is a reference to Ai’s prolific use of social networking site Twitter to get his message out.

“There is a force you cannot avoid,” says Ai’s character, played by Benedict Wong, as the play opens. He is standing in front of his new work, four connected walls which stand inside a gallery, surrounded by visitors and fans. He signs an autograph.

As the scene changes the walls become a prison cell.

Just hours before in Beijing, Ai said that the play based on Barnaby Martin’s book Hanging Man was the fruit of interviews that he hoped would help to demonstrate the monolithic truths of a Chinese state which holds him physically captive, but cannot seem to stop his ideas from seeping out.

“This society lacks transparency, lacks a platform and space for public opinion. So that’s why I accepted the interviews and the play finally worked out,” Ai said.

Howard Brenton’s play tells the story of the Chinese artist’s 81 days in custody.

Ai was arrested at Beijing airport in April 2011 before a flight to Hong Kong.

He was held without explanation before being charged with tax evasion and given a €1.8 million bill.

He supposedly confessed to the charge while in custody but later disputed it, losing his ultimate court appeal last September.

“I think the reason behind the play is to let the truth out, to let the people in the world understand what kind of condition we live in,” Ai said.

The telling of the story of Ai’s darkest hours to date is in keeping with the artist and the theme of the play – that personal expression is sacrosanct.

“Everything mentioned (in the play) is fact and it also is an artwork,” Ai said.

The play will be streamed for free on the internet, a first for a mainstream London theatre, allowing the story to reach a global audience.

“An artist’s job is about communication and expression. These are the core values of life, of being individuals.

“Most people don’t realise that they have to fight for this, but for us artists, it’s necessary,” Ai wrote in a column for The Guardian this week.

This role of the artist has frequently been at odds with the Chinese party line.

In the play Ai’s interrogators call him a con-man and a swindler, selling junk for profit.

A Chinese minister, when asked what should be done with Ai, says “get him to go back to painting leaves and pagodas”. (Reuters)