The aunt of an Alberta woman who has been released from custody in China says she believes it was a mistake by her niece's employer that resulted in her arrest.

Sarah McIver was detained earlier this month over a work-permit issue related to her teaching job, but her aunt Rhona McIver says Sarah is now on her way back to her hometown of Drumheller, Alta.

Rhona McIver said she believes her niece arrived in China to learn that the school she'd planned to teach at no longer had a job for her, so officials gave her work at another school.

"That's where the mistake got made," McIver said from Drumheller in an interview Saturday.

"She probably didn't even think about it."

McIver's arrest followed those of Michael Kovrig and Michael Spavor, two Canadians living and working in China, on allegations they were harming China's national security.

2 Canadian men remain in custody

China arrested Kovrig and Spavor separately after Canadian authorities detained a Chinese technology executive in Vancouver. Meng Wanzhou, the chief financial officer of electronics giant Huawei Technologies, is wanted in the United States on allegations she lied to American banks as part of an effort to get around sanctions on Iran.

China and Canada both insisted McIver's case was different from Kovrig's and Spavor's.

Rhona McIver said Sarah's mother and sister have driven to B.C. to pick her up. She explained that while in China, McIver adopted a puppy, and even though she was able to fly from China to Canada with the dog, there was a problem flying it to Calgary.

"One morning she was going to school and somebody threw out some pups, so she rescued one," McIver said, adding they could be back in Drumheller by Saturday evening.

McIver said her niece like to travel and had been to China before, but only as a tourist.

A spokeswoman for China's Foreign Ministry said last week that a Canadian woman had received an administrative penalty for illegal employment but did not provide further details.

A spokesman with Global Affairs Canada confirmed Friday that a Canadian citizen who was detained in China this month was released and has returned to Canada, but would not release further information due to provisions under the Privacy Act.