BERLIN (Reuters) - American actor River Phoenix has returned to the big screen 20 years on from his death after "Dark Blood" director George Sluizer salvaged the footage of his incomplete 1993 film and filled in the gaps with voiceovers.

Phoenix was considered one of the most promising performers of his generation before he died suddenly of a suspected drug overdose aged 23, 10 days before shooting on "Dark Blood" was scheduled to finish.

British actor Jonathan Pryce, who starred alongside Phoenix and Judy Davis in the story of a couple who get lost in the American desert, said he had no reason to suspect the young star was taking drugs during six weeks of filming together.

"I found him a remarkable young man," Pryce told reporters after a press screening in Berlin.

"I can't believe now looking back that he was only 23 at the time, a kind of old head on young shoulders. He was absolutely delightful and wonderful to work with.

"In all the weeks we were together in Utah ... at no time did I experience him using drugs or abusing drugs in any way, shape or form. I'm not a drug user myself but I'd have known. It was a time in his life when he was very committed to not using drugs. I loved him a lot and I love his memory."

In "Dark Blood", Phoenix plays Boy, a disturbed young widower of Native American extraction, who rescues wealthy couple Harry and Buffy, played by Pryce and Davis, when their vintage Bentley breaks down in the middle of the desert.

Fearful of the forbidding landscape of scrub and canyon and the fierce heat, the couple are relieved, and Buffy is initially attracted to the dark, brooding loner who lives in an isolated wooden shack on the top of a hill.

But their unease begins when he shows them a candle-lit bunker carved into a canyon where he believes he and a mate can be saved from the end of the world, and that unease turns to fear when he refuses to take them to the nearest town.

MIRACULOUS JOURNEY TO SCREEN

The fact that "Dark Blood" was ever made is a minor miracle in itself.

In 1999, Sluizer discovered the film reels were about to be destroyed by the company that insured the movie and so flew from the Netherlands to Los Angeles just in time to rescue them.

In 2007 the Dutch filmmaker, who is now 80, suffered a serious illness and so decided to try and finish what he had started. He estimated that 25 percent of the footage was missing, and sound and image often did not match.

Sluizer was forced to adjust his script to fit what he had, and to add voiceovers explaining the gaps in the action, but the overall effect is surprisingly coherent.

Whether wider audiences will be able to watch the completed film remains to be seen, with Sluizer yet to cut a deal with the company controlling the rights.

"They are very tough," he said. "They are billionaires, money market people apparently who by mistake I would say have in their stock ... a film, and they don't care about movies and they don't care about culture, they care about money."

He did, however, have the blessing of members of the Phoenix family, which includes River's younger brother and fellow actor Joaquin.

"We've been in touch with the mother of River and had correspondence," he said, adding that the family was not participating in the launch of the movie in any way.

"The relationship is that the mother of River wished us the best with the film."

Sluizer set the film in Native American territory contaminated by nuclear tests and all but abandoned.

Asked why he had cast Phoenix in the lead role, the director replied: "I chose him because I wanted a contrast between what was known about ... him, what he looked like, with this kind of weird, a little bit mad character."

He offered the tantalizing prospect of more footage coming to light, saying some reels may have been found in London.