TOKYO — The great escape of former Nissan boss Carlos Ghosn and his tirade against Japan's system of "hostage justice" may have grabbed the global spotlight, but there are many more foreign workers trapped in Japan who cannot find a way to leave.

A legal case brought by a ­30-year-old Filipina woman is drawing attention to a disquieting practice in Japan: Many employers confiscate the passports of foreign workers, especially Asians in low-status jobs, and refuse to return them even if the employee wants to leave the company, lawyers and labor rights activists say.

Effectively, the workers are trapped in low-paying jobs where they may be bullied or abused but are unable to seek employment elsewhere because their passports are held hostage.

“The fact that the company keeps the employees’ passports in their custody and makes them work corresponds to forced labor, which is not allowed in Japanese law,” lawyer Shoichi Ibusuki said at a news conference Thursday at the Foreign Correspondents’ Club of Japan (FCCJ).

The case comes about a year after Japan implemented a new immigration law that aims to attract more foreign workers and fill the gaps created by an aging domestic workforce, and it throws a harsh spotlight on the reality of employment here for many Asians.

The woman, whose name is being withheld to protect her privacy, studied Japanese at a language school from April 2017 to May 2019 and then decided she wanted to work in Japan, according to Makoto Iwahashi of the labor rights group Posse.

After picking up a flier at the immigration office in Yokohama, just outside Tokyo, she visited a local immigration law firm for advice on how to convert her visa into an employment one.

The firm offered her a job as an interpreter. She surrendered her passport, college transcript and college diploma so the company could process her visa application. She signed a form in Japanese — that she said she did not understand — giving her employer the right to keep the documents indefinitely, even if she quit working there.

After a month at the company, she discovered she was being paid only 100,000 yen ($910) a month, less than she needed to live on. When she asked to leave and for the return of her passport, the company said, “If it’s returned to you, then you’re going to run away,” she recounted.

I felt so worried, and I just didn’t know what to do,” she said in a video shown at the FCCJ. “I’m afraid what would happen to me if I don’t have those documents. My passport is my personal identity. How can I find a job or even to go back to my country if I don’t have it?”

The company, Advanceconsul Immigration Lawyer Office, declined to comment, refusing to speak to the media.

Ryo Yoshimura, an official in the foreign workers division of the Ministry of Health, Labor and Welfare, said the ministry is aware of the issue but will not comment on individual cases or “on how we would respond going forward.”

With financial support from Posse, the woman filed a lawsuit in Yokohama on Jan. 16 for the return of her passport and graduation documents, as well as for unpaid wages and damages.

Iwahashi and Ibusuki say they hope the case will force thegovernment to change the law to protect vulnerable foreign workers.

After several civil cases, the government enacted legislation in 2017 to protect the rights of foreign workers admitted under a technical intern training program. The law banned employers from retaining the passports of those workers, but it did not extend the protection to other foreign workers or foreign language students.

Ibusuki said business operators in Japan “very often” keep the passports and graduation certificates of foreign workers to curb their demands, silence protests against misconduct and prevent them from quitting.

The practice is also common at language schools in Japan, he said, to prevent students from changing schools. Ibusuki said ­­30 Vietnamese students visited his law firm last week, complaining their language school was withholding their passports, with another 30 in the same situation.

Iwahashi said the problem was “very, very prevalent” but underreported.

The new immigration law, passed in December 2018, aims to attract 345,000 foreign workers over five years, but critics say it fails to protect the rights of those workers or deal with questions of social inclusion.

The law was a response to Japan’s demographic decline — a slow-burning crisis caused by a low fertility rate, shrinking workforce and aging population that places a huge future burden on the economy as the tax base shrinks and the number of dependents grows. Many industries face labor shortages, especially in the run-up to the 2020 Tokyo Olympics.

Ibusuki said he testified at a parliamentary hearing onthe immigration legislationin late 2018 and warned that if the country wants to attract more foreign workers, it needs to protect their rights.

“But the government, as well as the parties in power, did not listen to my opinion,” he said. “Most politicians are not interested in this issue.”

There is a wider problem with workers’ rights in Japan’s highly stratified society, but foreign workers are particularly vulnerable when their passports are taken, because they don’t have the money — or the time to stay in Japan — to fight long court battles with their employers.

Ibusuki and Iwahashi said companies were well aware of that and were taking advantage of it.

“They calculate how much it’s going to cost to hire a lawyer, how much it’s going to cost to get your passport issued,” Iwahashi said. “And they’re doing this intentionally and deliberately.”

The Filipina worker even struggled to get a replacement passport issued by her embassy, Iwahashi said. “To get it reissued, it had to be lost or stolen,” he said. “And for it to be reissued as lost or stolen, you had to get a police report.”

Eventually, after multiple visits, the embassy agreed to issue a new passport in the next few months, he said.