Colombia’s Ministry of Labor has launched an investigation into TikTok subcontractor Teleperformance, relating to alleged union-busting, traumatic working conditions and low pay, first revealed by TIME and the Bureau of Investigative Journalism.

Teleperformance employed TikTok content moderators who earned as little as $10 per day, the report by TIME and the Bureau found. The workers were regularly required to witness videos depicting murder, child abuse and sexual violence as part of their duties. Attempts by workers to unionize were met with intimidation and threats.

Read More: Behind TikTok’s Boom: A Legion of Traumatized, $10-A-Day Content Moderators

“We have officially decided to start an investigation against Teleperformance,” tweeted Edwin Palma Egea, a minister for labor relations in the Colombian government, on Tuesday. “We have notified the company and invite all workers and trade union organizations in the country to provide us with evidence of alleged violations of labor standards.”

“According to a report dated October 20, 2022, presented by TIME magazine, a series of acts were exposed that violate the right to dignity, work and social security towards workers who moderate TikTok videos by the company Teleperformance in Colombia,” an official notice of the investigation dated Oct. 26, seen by TIME, says. “This work has led the workers of this company to present affectations in both their physical and psychological health.”

In a statement, Teleperformance said it had not yet received an official notification of the investigation. “Should we receive any official notification we will respond to it appropriately at that time,” a spokesperson said Wednesday. TikTok did not respond to a request for comment.

Teleperformance, a call-center giant based in France with offices worldwide, is one of Colombia’s largest employers, with more than 42,000 workers in the country. While its TikTok moderators are a small fraction of that number, they perform an important role for the short-form video giant, making sure that the feeds of users in Latin America remain free from traumatizing content that might cause users to quit the lucrative app.

Shares in Paris-listed Teleperformance fell 34% following the announcement of the Colombian labor department investigation, and trading of the stock was halted at the company’s request, according to MarketWatch. Teleperformance later announced it would spend €150 million ($152 million) buying back its shares, saying it believed the move to be “a good usage of its available cash.”

Social media companies around the world regularly turn to third-party contractors in developing countries to do the traumatizing but integral work of content moderation. For years that work occurred behind a veil of secrecy, but recent reports in the press have inspired a wave of legal and regulatory scrutiny. The investigation in Colombia comes just months after a former Facebook content moderator filed a high-profile lawsuit in Kenya, alleging union-busting and other violations of the Kenyan constitution, after blowing the whistle in an investigative report by TIME.

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The president of Utraclaro, the union at the center of the union-busting claims against Teleperformance’s TikTok workers in the TIME and Bureau report, welcomed the decision in a tweet. “It is a very important development,” Yuli Higuera wrote. “Call center companies commit abuses with their workers [but] it remains invisible since the workers themselves do not report it out of fear.”

The UNI global union, an international workers’ rights umbrella group that Utraclaro is a part of, told TIME in a statement that it would cooperate with the Colombian government’s investigation. “We welcome this action by the Colombian labor ministry to address allegations of poor working conditions at Teleperformance,” UNI’s regional secretary for the Americas, Marcio Monzane, said in the statement. “The company is one of the biggest private employers in Colombia but it is failing to take workers’ welfare seriously. The TIME exposé showed how content moderators at Teleperformance need a voice on the job as they struggle day after day with low pay, punishing schedules and a lack of adequate psychological support. UNI and its affiliates will cooperate with the ministry in its investigation.”