There is a very limited amount of available documentation relating to the master of doctrine known as Phật Trùm. Even his religious alias is yet to be accurately interpreted. It has been argued that he was of Cambodian origin and his true lay name was Pucombo. However, this claim can not be backed up by any Bửu Sơn Kỳ Hương or Hòa Hảo Buddhist sources. In fact, historical sources did mention some activities of one member of the Khmer royal family known as Pucombo in 1866. Yet there have been no positive proofs that Phật Trùm and Pucombo were the different names of one person.
There have also been conflicting reports with reference to Phật Trùms incarceration by the French colonial authorities. It has been argued that in 1870, Phật Trùm was detained by the French police and sent to exile outside of Vietnam. However none of the available documentary sources mentioned an exact locale of Phật Trùms exile. As a matter of fact, during the 1860-1880s period, the French did deport some Vietnamese nationalists. Notably, in 1864 Nguyễn Hữu Huân was expelled to Réunion Island. In 1868, Từ Phong, an activist of Bửu Sơn Kỳ Hương, was deported to Cayenne, and Trần Văn Cương was also detained in Cayenne in 1872-1882. In 1883, another activist of Bửu Sơn Kỳ Hương known as Nguyễn Văn Vi was imprisoned in Côn Đảo Island. In 1889, another anti-French activist, Bùi Văn Thuận, was also detained there. However, the locale of Phật Trùms reported incarceration and alleged subsequent exile still remains a matter of debate.
Before his incarceration, Phật Trùm lived in the Tri Tôn area of Châu Đốc province. His evangelizing patterns were more or less in line with Tây Ans conversion methods. Not surprisingly, Phật Trùm did employ healing as a main proselytizing tool. Hence he was recognized as an adherent of Bửu Sơn Kỳ Hương tradition. Phật Trùm was also known as Đạo Đèn or Candle Monk because as a healer he used candle wax to make cures. His followers believed that Phật Trùm was Tây Ans avatar.
During this period, southern Vietnam became an arena of the anti-French Cần Vương movement. Some resistance leaders, notably Nguyễn Trung Trực and Trần Văn Thành, had affiliations with the Bửu Sơn Kỳ Hương tradition. This is why the French tended to persecute all adherents of Bửu Sơn Kỳ Hương.