A Christian missionary reported missing in Sudan is being held by authorities in Khartoum, The Foreign Desk has learned.

Petr Jasek, 52, a Czech missionary and documentary filmmaker, originally travelled to Sudan in 2015. He has been listed as missing since December on Interpol’s website for missing people, according to Czech media.

Authorities in the Czech Republic have revealed that he has been detained by Sudanese authorities where he faces possible charges of entering the country illegally as well as allegedly falsifying an account of Muslim persecution of Christians.

The claims refer to a purported videotape in which Jasek films a local Christian man who sustained burns at the hands of Muslims. The alleged victim later told authorities that his words had been taken out of context by Jasek and that his wounds were the result of a car accident.

Czech diplomats have held discussions with their Sudanese counterparts in an attempt to secure Jasek’s release and avoid a trial in Sudan, according to Czech foreign ministry spokeswoman Michaela Lagronova. A Czech official has also been allowed to visit Jasek in prison.

Jasek’s case is further complicated by Sharia law, a framework of Islamic law which Sudan’s legal system is based upon.

If found guilty, he could face a harsh sentence, though according to CTK, the Czech Republic’s national news agency, it is not believed any of the alleged accusations would incur the death penalty.

Jasek is also active with Voice of the Martyrs, a U.S.-based organization, dedicated to assisting persecuted Christians worldwide. The organization is refraining from comment due to the sensitivities surrounding the case but has called for people to pray for Jasek’s release.

Last year, two Christian pastors from South Sudan who traveled north to Sudan were arrested on charges of spying and faced a trial carrying a potential death sentence. The pair were subsequently released after international outcry from governments and human rights groups.

Marginalization of Christians has dramatically increased since the secession of South Sudan in July 2011.

Sudanese President Omar al-Bashir, a hard-liner, has vowed to make Sudan a fully Islamic state operating under the strictest interpretation of Sharia Law, acknowledging only the Muslim religion and the Arabic language.