A Canadian MP has reunited his adopted daughter with her long-lost Sudanese siblings who were once feared dead.

Glen Pearson, the Liberal MP in London, Ontario welcomed Achen Roy and Ater Roy into his family on Wednesday when they arrived at Pearson International Airport in Toronto from Sudan with his wife Jane Roy.

The two children were reunited with their six-year-old sister Abuk, whom Pearson and Roy had adopted five years earlier.

Pearson and Roy, who have frequently performed humanitarian work in war-stricken Sudan, had been told that Abuk's siblings were dead.

An attack on the area where the siblings separated the family. The mother took Abuk, while two other relatives took Abuk's twin sister Achen and her half-brother Ater. However, the children's mother was killed when she stepped on to a land mine.

"Abuk had been left in the minefield for the day and was finally recovered by somebody," Pearson told CTV's Canada AM. "And we thought, why don't we try to adopt this child?"

The entire process took over a year. When the couple finally found Abuk, she was 15 months old, weighed just 12 pounds and was expected to die.

Pearson and Roy had heard of Achen and Ater but had been told they had been killed.

However, they were in for a surprise when they brought Abuk back to the village.

"We came off the plane and there, standing at the bottom of the stairs, was an identical person to Abuk and it was Achen and there was Ater as well. And so we realized we really had our work cut out for us for us to try to get them to Canada as well," Pearson told CTV's Canada AM.

Pearson and Roy decided that they would adopt the two children to reunite the siblings -- a process that took two and a half years -- but one that was worth the wait.

Malaria is a serious problem for children in the Sudan and the entire continent of Africa. According to United Nations estimates, malaria is the largest single cause of death for African children under the age of five, with more than one million children dying of the disease every year.

Abuk had bronchitis and malaria when she was adopted and Pearson and Roy will monitor 10-year old Ater and Achen to determine whether they have the type of malaria that re-occurs.

Pearson himself suffers from malaria, having contracted it in 1970 while doing aid work in Bangladesh in 1970. He suffers from the malaria attacks three to four times a year, which subjects him to delirium and nausea.

"I can get by fine but when you're a little child and you're malnourished and don't have water, malaria will kill you," Pearson said.

Along with his wife, Pearson is working to raise money to send low-cost bed nets that help to stop the spread of malaria to Africa. The bed nets ward off mosquitoes and can significantly reduce malaria transmission and child mortality on the continent.

Now that Achen and Ater have travelled to an entirely different continent, they can focus on adapting to their new surroundings, a process their more experienced sister Abuk is willing to help them with

"I have to teach them stuff and I have to help them," Abuk said.