According to the latest investigation by Tech Transparency Project (TTP), Lens Technology Co., a key supplier of touch screens for Apple, used thousands of Uyghur laborers from the predominantly Muslim region of Xinjiang in China.

This is not the first time that Apple's supply chain has been associated with alleged forced labor from the Xinjiang region, said The Washington Post, which first reported the TTP findings this week.

Another Apple's supplier, the Esquel Group, was also found to be involved in China's alleged forced labor program, in Xinjiang, said TTP, although China disagrees about the existence of forced labor in the country.

The TTP findings on Lens Technology comes amid news that Apple is actively lobbying against a bill that will sanction companies for participation in China's alleged forced labor program.

A thousand of these workers came from the Xinjiang city of Turpan in 2018, according to a release from the city's Human Resources and Social Security Bureau, said the Tech Transparency Project.

The workers were sent by the same Xinjiang government agency that supplied Uyghur laborers to O-Film, another Apple supplier who was recently added to a US government blacklist for its involvement in China's alleged forced labor program, TTP added.

Apple spokesman Josh Rosenstock denied that Lens Technology has received any labor transfers of Uyghur workers from Xinjiang, according to The Washington Post report.

Apple earlier this year made sure that none of its other suppliers are using Uyghur labor transferred from Xinjiang, said the spokesperson.

Lately, China has been facing criticism from human rights activists around the world for its treatment of the Uyghur Muslim minority.