Aust activist freed from Malaysia cell

Sydney woman Natalie Lowrey has been released after being detained for six days in Malaysia, where she was protesting against an Australian company's metals plant.

Ms Lowrey was arrested on Sunday while demonstrating at Lynas' controversial plant for rare earths, which are used in tech products like smartphones.

Police were weighing a charge of unlawful assembly, which carries a maximum two-year jail term.

But on Friday night, as the New Zealander was preparing to spend a weekend behind bars with no visitors, she was suddenly released on bail.

"It was a big surprise, I didn't believe it until I had changed out of my purple jail uniform," she told AAP.

"I felt very strong the whole week because I knew there were vigils all over Australia and Malaysia for me. I have a lot of people to thank."

Ms Lowrey was released along with 15 Malaysians who had also been arrested.

The lack of transparency around Ms Lowrey's detention concerned lawyers and NGOs, who collected more than 15,000 signatures on a petition to free her.

She has her passport back and plans to leave Malaysia next week.

First, the Bondi resident hopes to spend a few days in the area that inspired her to campaign against the Lynas plant.

Protesters say the plant, in the eastern state of Pahang, will leave behind radioactive waste that will endanger the community and the coastal environment.

Ms Lowrey on Saturday went for a swim at the beach, enjoyed a good meal and thanked local campaigners for their support.

"I feel very strongly that Australian companies have to be accountable for their actions overseas," she said.

"I will continue to show solidarity with the hundreds of thousands of Malaysians who want Lynas to leave."

Lynas says it is obeying strict human and environmental health safeguards to protect the health and safety of the general public.