 He conducted extensive correspondence with the International Labour Organization (ILO) regarding the conditions of Indonesian workers.Max White, Princen's friend and co-worker, stated that "Poncke believed that 'Labor rights are human rights', he saw no distinction".In 1992 he won the prestigious Yap Thiam Hien Human Rights Award – named for the Chinese Indonesian lawyer Yap Thiam Hien, a fellow human rights activist.