Lawyer and human rights advocate Dong Samuel Luak was in charge of the South Sudan Law Society, an NGO focused on promoting justice and the rule of law, between 2002 to 2013.
Luak fled to neighbouring Kenya in August 2013, after receiving death threats following his defence of Pagan Amum, the former secretary general of South Sudan's ruling party accused of an alleged coup plot.
Since South Sudan's conflict began in December 2013, Luak, who is the opposition forces SPLM-IO's deputy chairman for justice and human rights, has publicly condemned human rights abuses by South Sudanese government officials.
Luak was detained by Kenyan authorities on 23 January, prompting social media users to use the hashtag #WhereIsDong? in support of the activist.
According to Human Rights Watch (HRW), the refugee is being held at the Nairobi Area Police Headquarters. Subject to a deportation order, Luak is is at risk of a forced return to South Sudan, where he could face persecution, HRW said.
"Dong Samuel Luak has been a vocal advocate for human rights in South Sudan for many years," Leslie Lefkow, deputy Africa director at HRW, explained. Highlighting how men alleged to be linked to South Sudan's security services attacked Luak in his Nairobi home in October 2015, Lefkow said the activist is at "serious risk of arbitrary detention, torture, and other abuses if returned to South Sudan".
Another prominent South Sudanese politician, James Gatdet Dak, a spokesperson for opposition leader Riek Machar, was deported from Kenya in November 2016, and arrested upon arrival in South Sudan's capital, Juba. Gatdet Dak has since been held, without charge, at the headquarters of South Sudan's National Security Services.
Kenyan and international law prohibits the return of a refugee "in any manner whatsoever" to a place where their life or freedom would be threatened, and Kenyan authorities should ensure a refugee is protected. "Kenyan authorities should respect [Luak's] rights, allow him access to legal counsel and United Nations refugee officials, and immediately halt any deportation proceedings against him."
In recent years, however, Kenya has unlawfully deported refugees including prominent opposition members from neighbouring countries to their home countries. These were all recognised as refugees by the Office of the UN High Commissioner for Refugees (UNHCR).
South Sudan's war broke out on 15 December 2013, when President Salva Kiir, of the Dinka ethnic group, fired his deputy Machar, from the Nuer group, from his cabinet.