OSLO, Norway - Keiko, the killer whale star of the "Free Willy" movies, was buried today during the deep darkness of Nordic winter in a ceremony kept secret from the public and media.

"We wanted to let him be at peace," said Dane Richards, one of his caretakers. "He's free now and in the wild."

The roughly six-ton whale died Friday in a peaceful Norwegian bay where his team had been trying to reintroduce him to the wild. His trainers said the likely cause of death was the onset of pneumonia.

Richards said the burial in a pasture just yards from where Keiko, about 26, died was done in secret to avoid a media circus.

"He is probably the most famous being that was ever buried so quietly," Richards told The Associated Press. "We are amazed that it could go so quietly."

Keiko captured people's imagination through his stardom in "Free Willy," a film in which a young boy befriends a captive killer whale and coaxes him to jump over a sea park wall to freedom.

For Keiko, which mean's "Lucky One" in Japanese, fame resulted in a $20 million drive to free him from a Mexico City aquarium where he was languishing.

He was brought to the Oregon Coast Aquarium in 1996 and to Iceland, near where he was born in 1977 or 1978, for more rehabilitation and training for an eventual return to living in the wild.

The orca was released in mid-2002, and swam straight for Norway, on an at least 870-mile trek to the waters near the village of Halsa, on Norway's west coast, in late August 2002.

Richards said, despite the whale's size, the burial went smoothly. Machines dug an enormous hole near the waterline, under cover of darkness, and then slid Keiko slowly a few yards across the snow into his grave, he said.

"It was beautiful. He went to the grave quietly, quickly and peacefully, just like he died," said Richards.

Only seven people - his team, landowners who had provided a base and support, and the machine operator - witnessed the burial of a star that had attracted millions of visitors during his lifetime.

As a back hoe gingerly placed the last scoop of dirt into the grave, the weather turned violent, said Richards.

"It was almost surreal, there was hail, thunder and lightning," he said.

The grave site, a lush and grassy field during the summer, was covered with snow and barely visible by daylight Monday.

Halsa, a village of 1,750 people some 250 miles northwest of the capital, Oslo, may erect some sort of memorial, but nothing has been decided.

Normally, Norwegian fisheries authorities would order the remains of a large sea mammal towed to sea and sunk in deep water. However, they acted quickly during the weekend to give Keiko's backers, which included the Free Willy-Keiko Foundation and the Humane Society of the United States, permission to bury the celebrity on land.