Thai prisoners are being forced to make fishing nets for private companies under threat of punishment including beatings and delayed release, a Thomson Reuters Foundation investigation has found.

Jails around the country are using inmates to fulfill high-value contracts with Thai manufacturers, including one that exports nets to the United States, according to documents obtained under freedom of information (FOI) rules.

Former prisoners interviewed by the Thomson Reuters Foundation said prison officers threatened to beat them with batons, withdraw the right to wash or push back their release date if they did not meet stringent targets.