Because 'District 9' is set in South Africa, some may suggest that the film is a direct metaphor for the many problems that country has faced over the years.

The filmmakers say that though it's impossible to divorce the film from its setting, no direct metaphor is intended. "In South Africa, we have to deal with issues that generally people around the world try to sweep under the rug," says Sharlto Copley, who plays the lead character, Wikus.

Working with the thematic and visual ingredients of the short film as a springboard, Blomkamp and his writing partner Terri Tatchell fleshed out the character of Wikus, and introduced two central alien characters, Christopher Johnson and his son, Little C.J. (The writers gave the aliens human names, imagining the re-naming humans would do when admitting the aliens to our planet).

It was important to the writers that all of the characters, even and especially the aliens, were believable, recognisable ? well, human. Drawing on people they knew or were familiar with, the writers created a cast of characters who are an amalgamation of many people.

Blomkamp's childhood friend and collaborator, Sharlto Copley, takes on the role of Wikus van der Merwe, the MNU official charged with removing the non-humans from District 9 and moving them to the concentration camp of District 10. Copley had also worked on 'Alive in Jo'Burg', producing that film.

"Neill has found a very soulful way of approaching science fiction," says Copley, who has known Blomkamp for over 12 years. "The genre can be clinical, even cold and unemotional. But in Neill's hands, it resonates quite deeply. There's no particular message or big moral of the story ? it's just a melting pot of emotions that comes out."

Copley says that he was thrilled to continue working with Blomkamp. "There is a very small film industry in South Africa," he says. "So even if you meet someone else who wants to work in film, it's not necessarily a person that you can resonate with or gets your creative point of view. So I feel very fortunate that Neill's one of those people that I always got what he was trying to accomplish, and he saw things in me, too."

"A small amount of power goes a long way with Wikus ? he's an ordinary guy who likes to wield power in a bureaucratic way," says Copley. "That's why MNU promotes him ? they want a guy who will do things in an orderly, proper way."

"Wikus has a very bad day," says Peter Jackson. "Not only does he contract a mysterious disease that starts changing his DNA, but what makes it worse is that he becomes the key to unlocking the alien weaponry. For a moment in time, Wikus becomes the most important person on the planet."

'District 9' opens in cinemas on Friday, August 28.