However, although Sjam claimed in court that he joined the PKI in 1949, according to Mortimer he was listed (under the name of Kamarusaman) in the Suara Sosialis (Voice of Socialism) as a Socialist Party member undergoing intensive party training in Jakarta.
Namun, meskipun Sjam mengaku di pengadilan bahwa ia bergabung PKI pada tahun 1949, menurut Mortimer ia terdaftar (dengan nama Kamarusaman) di Suara Sosialis, sebagai anggota Partai Sosialis ia menjalani pelatihan intensif di Jakarta.