A major retrospective of the work of Chinese dissident artist Ai Weiwei opens at London's Royal Academy of Arts on Saturday, exploring his subversive exploration of human rights abuses.

The London exhibition is a landmark for the artist as it is the first in five years which he could personally supervise after having recovered his passport, confiscated by Chinese authorities in July 2011.

"He said that the emotional impact of coming to London to see the show is extraordinary," said RA artistic director Tim Marlow.

The last public exhibition of his works that Ai Weiwei was able to attend was his "Sunflower Seeds" at the Tate Modern, between October 2010 and May 2011, Marlow said.

"It was then that he was incarcerated and that his passport was taken away."

The Chinese dissident is returning to the British capital in anything but low-key style.

Visitors who pass the courtyard of the RA in central London will see his monumental sculpture "Tree", eight large trees made from pieces of dead trees from southern China.

The work has been discussed as a symbol of China -- a combination of different ethnic peoples brought together to form one nation.

The RA crowdfunded the money to bring the sculpture to London, raising �124,000 ($190,000, 170,000 euros) from 1,300 backers.

Inside the gallery, works by Ai Weiwei are displayed in 11 rooms, each with a theme organised by project, period of life or material used by the artist.

The largest section focuses on his work on the Sichuan earthquake of 2008, which killed tens of thousands of people.

Two enormous wall panels list the names of some 5,000 school children who died in the disaster due to poor building quality.

Another huge sculpture is "Straight", an installation of 90 tonnes of steel rods which were straightened by hand after being mangled in the quake.

The work drew increased scrutiny from the Chinese government, who Ai Weiwei suspects of holding back information on deaths in the disaster.

- Political undertone -

"His work has almost always had a social and political undertone and even in the works that don't seem political, there's a political undertone," Marlow said.

"Even in the most explicit works, like Straight, there is also a kind of poetic transformative dimension too, that's why he is a good artist."

Another example of this is "Fragments", a structure made of pieces of ancient temples that have been destroyed. Seen from above, the haphazard construction forms a map of China.

Visitors can freely walk underneath and through the sculpture, a comment on freedom of movement in the country.

The materials used are never random, according to the exhibition curator Adrian Locke.

"Often understanding the context is key to admiring the work and the full impact of the work," Locke said.

For example, the white marble used by the artist in many of his works comes from the same quarry that is used for the Forbidden City and the mausoleum of the founder of modern China Mao Zedong in Tiananmen Square.

The penultimate part of the exhibition recalls Ai Weiwei's 81 days in detention in an unknown location in spring 2011, through six scenes staged in huge metal boxes that viewers can peek into through small gaps to see lifelike figures of him and prison guards.

"S.A.C.R.E.D.", first shown at the Venice Biennale in 2013, shows Ai Weiwei's experience of being incarcerated under intense surveillance.

"He showers, he sleeps, he eats, he defecates, and every moment a guard or two guards are less than a meter away from him," Marlow said.

None of the artist's work will return to China after the exhibition, according to the artistic director.

"Still in China I have to work very carefully if I want my work to be showing," Ai Weiwei explained at a press conference last week.

"I have to be very careful, there's always censorship there, unless you don't care and don't want to show it there."