Gustafsson from Värnamo, southern Sweden, returned home in June after five years and seven months in captivity in Mali. Sweden has refused to provide details about how his release was secured, describing it only as the result of "years of efforts" by police, diplomats and Swedish and international authorities.
On Thursday Gustafsson held a press conference in Stockholm for the first time.
"I'd like to take this opportunity to thank my friends and people I know that don't speak Swedish. I have received so many warm messages after my release," he said in English before changing to Swedish. "I'm very happy to be here today. I didn't always think I would get home again."
He thanked Swedish authorities for keeping in close contact with his family and keeping them informed about his situation during his captivity. He also thanked charity organization Gift of the Givers, which had been working to secure his and his fellow hostages' release.
"These years have been tough, both for me and my family. Five years and seven months. It warms my heart every time anyone welcomes me home," he said.
Johan Gustafsson speaking to journalists on Thursday. Photo: Vilhelm Stokstad/TT
Gustafsson, 43, was abducted in Timbuktu, northern Mali, in November 2011 along with South African national Stephen McGown and Dutchman Sjaak Rijke. Rijke was freed in April 2015 by French special forces and McGown was released last week.
Gustafsson was on a motorcycle trip from Sweden to South Africa when he was kidnapped. He, Rijke and McGown were seized along with several other Westerners by a group of armed men while on the terrace of their hotel. Rijke's wife managed to escape, but a German who tried to resist the abduction was killed.
Al-Qaeda's North African affiliate al-Qaeda in the Islamic Maghreb (AQIM) claimed responsibility for the kidnappings. It was one of several jihadist groups that took control of Mali's north in 2012 before being ousted by a French-led military operation launched in January 2013.
Johan Gustafsson with his parents just after his return to Sweden. Photo: Simon Stanford/TT
The Swede told journalists on Thursday that he looked for opportunities to escape, but in summer it was too hot in the desert. He then tried to pretend that he had become Muslim, to increase his chances of survival.
"I told them I wanted to convert to Islam. That was the only thing I could think of that would buy me some time, even though I did not have much hope that it would work," he said.
He was then allowed to walk around freely in the camp and prayed together with his captors.
"I pray with them and eat with them. I act like they do. I act like I'm an ordinary Muslim, not like a jihadist. During this time you get to know them. I feel inside of me that they are the enemy, but if there is anything I can do I do it," he said.
"I didn't know anything about Islam, so I'm not sure how believable it was. But I think they saw it as their duty to accept it, even though I have a hard time believing that they actually believed me."
He said he kept plotting an escape and managed to leave once, while his kidnappers were distracted. He walked through the desert for two days and two nights before his captors found him again and drove him back to the camp.
Johan Gustafsson in a hostage video released by al-Qaeda in 2015. Photo: Handout
Speaking about his release, he said it happened towards the end of Ramadan. He was tired after not having eaten all day. A driver came to the camp, greeted the leader and told Gustafsson to pack his things.
They drove for some time, changed driver and kept going through the night until they reached a group of vehicles.
"I hear, in clear Swedish: 'Johan?' I answer 'yes'. I walk over and am greeted by a bunch of Swedish police officers with tears in their eyes. They form a protective wall around me until we land at Arlanda. There, [Sweden's Foreign Minister] Margot Wallström meets me and takes me to my family," he said.
Sweden's policy is not to pay ransoms in the event of kidnappings, and Gustafsson said he hoped that no ransom had been paid, adding that he did not know why he was released in the end.
"I hope they were just really fed up with me," he joked.