Australian student Alek Sigley, center, is escorted as he arrives at the airport in Tokyo on Thursday, July 4, 2019. The Australian student who vanished in North Korea more than a week ago arrived in Tokyo Thursday, July 4, 2019. Photo: AP Photo/Eugene Hoshiko.

Canberra - Australian student and tour operator Alek Sigley, who was set free after several days of detention in North Korea, has thanked those involved in his release, saying he intends "to return to normal life."

The 29-year-old student from Perth had not been in contact with his family and friends since June 24. He was released on Thursday and arrived overnight in Tokyo where his wife lives, after a brief stopover in Beijing. It is not clear why Sigley was detained.

"I just want everyone to know I am OK, and to thank them for their concern for my well-being and their support for my family over the past week," Sigley said in a statement released from Tokyo on Friday.

"I'm very happy to be back with my wife, Yuka, and to have spoken with my family in Perth (Australia) to reassure them I'm well."

"I intend now to return to normal life but wanted to first publicly thank everyone who worked to ensure I was safe and well," he said.

Sigley thanked Kent Harstedt, Sweden's Special Envoy to North Korea, for his efforts to secure his release, along with Australian Prime Minister Scott Morrison and Foreign Affairs Minister Marise Payne. 

Morrison had discussed Sigley's disappearance with world leaders at the G20 summit in Japan over the weekend and had asked Sweden for help in securing his release.

Australia has diplomatic ties with North Korea but does not have an embassy in the country. It conducts consular work with the help of the Swedish embassy in the North Korean capital Pyongyang, where Sweden has had an embassy since the 1970s.