Would-be flight attendants in South Korea have accused Indonesia's national airline of making them strip nearly naked and have their breasts handled in medical check-ups, provoking a storm of criticism.

Several dozen candidates for 18 highly-coveted female flight attendant positions with Garuda Indonesia were required to strip down to their panties to screen out those with tattoos or breast implants, one applicant told AFP.

She declined to be named, saying she was still waiting to hear whether she had got a job after the tests last month.

"The hand examination on breast was held since those with implants can have health issues when air pressure falls during flights," Yonhap news agency quoted an airline official as saying.

Cabin crew are banned from having tattoos and workers hired in other countries such as Japan and Australia were also subject to a similar process, the agency quoted the official as saying.

Garuda Indonesia's Seoul office denied part of the accusation, saying job applicants did not have to remove their bras and its staff only "lightly tapped (the) upper side of their breasts."

"Those who passed the medical checkup said they felt no shame in the process," the firm said in a statement, adding it was common for airlines to check if job seekers had tattoos or body implants.

But the move baffled industry peers and angered women's rights groups, which called the process unnecessary and intrusive.

Kim Da-Mi, a Seoul-based activist with the Sexual Violence Relief Centre, urged the state human rights agency to take action, telling AFP: "I wonder if such a practice is acceptable in Indonesia."

Indonesia has the world's largest Muslim-majority population.

"We've never heard of or done such checkup on flight attendants," said a spokesman for South Korea's flag carrier Korean Air, calling the Jakarta-based airline's tests "bizarre".

"I wonder if that means passengers with breast implants should not fly also," he told AFP.

Competition for flight attendant jobs is fierce in South Korea, where the role is seen as offering high pay and travel opportunities, and thousands of young women prepare for years before applying for vacancies.