Gustafsson and 42-year-old Stephen McGown were the longest-held of a number of foreigners seized by Islamic extremists in Mali, where several armed groups roam the West African country's north.
The South African government has insisted that no ransom was paid to free Stephen McGown, held hostage by Al-Qaeda in Mali for almost six years, despite some media reports saying $4.2 million was handed over.
He was released with Swede Johan Gustafsson, 42, and in their first appearance since freedom, the pair said they were not clear whether any ransom was paid for their release.
"You want to believe, but you're exhausted of really coming down with a bang after they tell you you should be going home soon".
McGown also said he found out about his mother's death just minutes before he arrived home in South Africa.
Rijke was released in April 2015 by FranceÂ´s Special Forces and McGown ended his captivity on July 29. "I try to see the best in everything, but his is the one thing I'm unable to really understand". "I didn't want to come out an angry person".
Mr McGown appeared at the press conference with long hair and a beard after many years spent in the desert.
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He said: "Before the desert, I was a Christian".
Mr McGown said he did not believe his captors knew his nationality when they caught him but had wanted him to be from the United Kingdom because British captives were more valuable to them.
He described how al-Qaeda militants gave him clothes, food and medication, but despite that, "you always knew you were a prisoner", he added.
Sweden has insisted it never paid any ransom and that Mr Gustafsson's release was obtained through negotiations.
Imtiaz Sooliman, head of the Gift of the Givers charity which helped to free McGown, said the kidnappers at first demanded 10 million euros ($11.7 million) for each of the three hostages. "I entered (Islam) of my own accord", he said.
McGown said he was "in the dark" about world events over the last six years as the hostages only had a radio for a short time and no books in English.