Sami Atabani said he hoped the Canadian government would consider evacuating his adopted sister, 43-year-old Kholoud Yagoob Abdallah, even though she does not hold Canadian citizenship like the rest of his close relatives.
Abdallah lives with her seven children in Omdurman, one of the three cities that makes up Sudan's wider capital and has seen frequent fighting between the army and the paramilitary Rapid Support Forces.
She moved away from the heaviest fighting, but is still in danger.
"We are extremely worried for their safety. I can't tell you how distressing that situation is for us as a family," Atabani said, adding that they had struggled to reassure his 91-year-old mother about Abdallah's safety.
Atabani says his parents were unable to legally adopt Abdallah partly due to complex adoption laws in Sudan, becoming her legal guardians instead.
But that does not allow her to be considered an immediate family member of Canadian citizens and qualify for the evacuations that Canada and other countries have carried out from Sudan.
Canadian authorities told him she could apply to come to Canada as a refugee, but six of her children lack passports.
"She cannot get to a third country, she doesn't have passports, it is impossible for her to leave the country," said Atabani, who lives in Britain.
A spokesperson for Immigration, Refugees and Citizenship Canada said that while the IRCC could not comment on individual cases, Canada had taken measures to "assist Sudanese nationals affected by the conflict."
