The script for "Gandhi"-director Richard Attenborough's next film is a closely guarded secret, but not because of any standard movie business paranoia. It's a secret for security and political reasons.

Next spring Attenborough will be behind the cameras for a $20 million film about apartheid in South Africa. A central figure in the film will be the late activist Steve Biko, but beyond that the director won't give any details or even disclose the name of the screenwriter, who is traveling in and out of South Africa doing research.

The Universal film will probably be shot in Zimbabwe or Kenya. The South African government was interested in cooperating, says Attenborough, provided it had international censorship rights. He naturally declined, and when he went to South Africa last year to research the movie, he says, the government "virtually ran us out of town" . . .

Two very different sides of Washington will be on cinematic display before long. For fans of political wheeling and dealing there's "Power," a story of political powerbrokers played by Gene Hackman and Richard Gere. Gere's amoral, profit-oriented character is the focus of the film, which also stars Julie Christie and Kate Capshaw. Most of the shooting took place in New York, but the film crew set down for two days in Washington (once in early April, again May 1), and will soon finish with a brief stay in Mexico.

While the relatively big-budget "Power" crew has been flitting in and out of town, a smaller-scale production has been shooting entirely in Washington. "Good to Go" deals with the city's go-go scene, which in the film is the subject of an investigation by a reporter played by Art Garfunkel, who initially blames the high-energy music for a black teen-ager's murder but of course winds up a fan. Local go-go entrepreneur Maxx Kidd is played by actor Robert Doqui in the film, which is being directed by rock video veteran Don Letts on a budget of less than $1 million. It will be in the theaters by mid-August, about the time Sidney Lumet will be busy with the post-production work on "Power" . . .

Jim Henson usually works with Muppets in his films, but he'll soon get a chance to work with the real-life David Bowie, who's been signed to play one of the two flesh-and-blood roles in the creature-fantasy film "Labyrinth," which Henson is directing in London for executive producer George Lucas . . .

Sigourney Weaver will be back on board that unlucky spaceship in the sequel to "Alien," which starts filming in England this fall. None of the other actors from the original will be around, since they were all eaten in that movie . . .

Only one week to go before the first batch of summer films hits the theaters, which has got to be good news for moviegoers who've been less than enthusiastic about most of the releases of the past few months. The critics have been even less enthusiastic -- rarely have so many unanimously panned films topped the box-office list week after week, from "Police Academy II" to "Moving Violations" to "Stick" to "Code of Silence."

One of the first summer films out of the gate will be the 14th James Bond movie, "A View to a Kill," which continues with the tradition of an elaborate, expensive opening sequence. This time, in fact, the pretitle sequence -- six minutes of Bond evading the Russians on a wild chase through Siberian hills and across a frozen lake -- cost $1.5 million to shoot. That's half again as much as the entire cost of 1963's "Dr. No," the first Bond movie.