A factory in Indonesia making clothes for Ivanka Trump’s brand pays its employees the worst salaries in Asia. There is anti-union intimidation and women are offered a bonus if they don’t take time off while menstruating, an investigation by the Guardian has revealed.

The Guardian has spoken to more than a dozen workers at the fashion label’s factory in Subang, Indonesia, where employees describe being paid one of the lowest minimum wages in Asia and there are claims of impossibly high production targets and sporadically compensated overtime.

The workers’ complaints come only a week after labour activists investigating possible abuses at a Chinese factory that makes Ivanka Trump shoes were arrested.

The activists’ group claimed they had uncovered a host of violations at the plant including salaries below China’s legal minimum wage, managers verbally abusing workers and “violations of women’s rights”.

In the Indonesian factory some of the complaints are similar, although the wages paid to employees in Subang are much lower.

According to a photo of a timetable one worker showed the Guardian, the production targets, broken down for every half hour between 7am and 4pm, are between 58 and 92 garments per period, while the actual numbers produced are recorded as 27 to 40.

“The management is getting smarter: they tap out our ID cards at 4pm so you can’t prove anything,” said Wildan, a 25-year-old male worker.

Seven workers also said they were subject to verbal abuse, being called things like “animals, moron and monkey”. Otang said this, too, was fairly common.

Beyond this, the factory also has a pattern of firing workers right before Ramadan and rehiring them a month later, to avoid paying a “religious holiday bonus”, according to several workers. Indonesian law dictates all workers are owed a holiday bonus according to their religion, which works out to at least a month’s wages or more depending on seniority. In May 2017, there were about 290 people fired before Ramadan, according to Toto Sunarto, a leader of the SPSI union in Subang.

PT Buma, a Korean-owned garment company started in Indonesia in 1999, is one of the suppliers of G-III Apparel Group, the wholesale manufacturer for prominent fashion brands including Trump’s clothing.

Many Buma workers know who Ivanka Trump is. Alia noticed her labels popping up on the clothes about a year ago.

There are currently 2,759 workers at Buma, according to the regional manpower office, of which the total unionised workforce is about 200, split between two unions.

For the majority of non-union Buma workers, their job is a run-of-the-mill hardship to be endured. About three-quarters of them are women, many are mothers and several, like Alia, devote almost all their income to children with whom they can’t afford to live.

Sita, 23, is one such worker. She had to drop out of college when her parents got sick, and started working at Buma last year. She told the Guardian that her contract will be terminated soon, after seven months of work.

“That’s one of the company’s ways to cope with extra expenses,” she said. As a contract worker, she will not get any severance. “I can’t stand it anymore. I work unpaid overtime every day and still earn just 2.3 million [rupiah] a month. I’m planning to move from Subang, where the minimum wage is too low. But I don’t know where to go yet. I haven’t got any connections.”

Indonesia has the largest gap among Asian countries between high and low wages for unskilled garment workers, according the International Labor Organisation. None of the workers the Guardian spoke with have ever received performance-based raises, only federally mandated ones – even though some of them have worked at the factory continuously for seven years.

The Guardian approached the White House for comment. None was forthcoming at time of publication. The Ivanka Trump brand’s public relations company declined to offer any comment.