Said Karim, 34, a resident of the Kharkha, was one of two people arrested by police on Wednesday after police found eight stolen firearms and 300 rounds of ammunition in his house.
Police also seized weapons and knives, his wife said. Karim and the suspected thief are reportedly married.
Karim’s son, Mohammad Ali, told Gulf News: “The police said my father’s family was living illegally and they had to arrest us just to prevent them from moving further. What can we do? There aren’t any other options.”
Karim is understood to have fled to Sudan in December 2010 following a police stop near the border in South Sudan’s Nuba Mountains.
But police were unable to detain him or his wife at their home on Tuesday because he is believed to have fled again, according to a police source.
Karim reportedly contacted police through Facebook and said he was returning to South Sudan following a police stop.
Police had been suspicious of the married couple’s identity and had searched Karim’s house as part of a wider raid which led to the discovery of explosives, guns and ammunition.
Karim’s neighbours, however, alleged that the neighbours had helped him in returning to Sudan.
Karim’s family told the Nuba news website that his wife is from a wealthy family in the city of Tewa, where he began working in the construction industry.
Karim had been living in the Kharkha since 2004 and had worked as a driver for the city, its president Ahmed Idris told reporters.