Image copyright Reuters Image caption Sandra covers her head with a cloth to protect herself from the public gaze at Buenos Aires Zoo (file photo)

An orangutan which spent 20 years in an Argentine zoo is being moved to a US animal sanctuary after being granted the same legal rights as humans.

Lawyers won a landmark appeal for Sandra in 2014, arguing she was being detained in Buenos Aires illegally.

The ruling found her to be Argentina's first "nonhuman person, with the right to liberty".

The 33-year-old arrived in Kansas on Friday and will undergo tests before moving to her new home in Florida.

Judge Elena Liberatori - who has a picture of Sandra in her office - told AP news agency she wanted her ruling to send a message: "That animals are sentient beings and that the first right they have is our obligation to respect them."

Sandra was born in an East German zoo and sold to Buenos Aires in 1995.

The orangutan spent much of her life in a solitary enclosure and regularly tried to avoid the public. She had a daughter in 1999, but the baby was taken away from her and sold to an animal park in China.

Her legal victory brought international fame to the orangutan, and set a precedent for apes to be legally deemed people rather than property.

Bubbles

Until this week - nearly five years later - Sandra remained at the site of the zoo, which closed in 2016 following reports of animal cruelty. The zoo is now being rebuilt as an "eco-park" with improved living standards for animals.

An Argentine court approved her transfer to Florida's Center for Great Apes in 2017, though her journey was delayed by applications for US permits.

The 100-acre sanctuary is home to chimpanzees and orangutans which have been freed from circuses, labs, zoos and private collections. Michael Jackson's former pet chimpanzee, Bubbles, is among several famous residents.

Sandra will join 21 other orangutans, and will be free to move between 11 outdoor areas where the great apes live.

"We're eager to meet her, she's a lovely orangutan" said Patti Ragan, the Center's founder.

Speaking to the BBC, Ms Ragan said she was happy that Sandra's story was bringing public attention to orangutans, one of the world's most endangered animals.

But she added that the sanctuary was working to ensure this heightened publicity wouldn't impact on Sandra's transition into her new home.

"We don't want any distractions," said Ms Ragan. "We just want her to have peace when she gets here".