Avicii's father insists that he often entertains long conversations with "Wake Me Up" filmmaker for his mental health, claiming to have seemed "happy" before his death.
He added: "When she was in a bad situation, she always called me, we talked a lot about her thoughts about life, about her thoughts about meditation, about love … we had long chats, often an" now or so, on the ocean.
"If you are very happy or extremely happy, it is not so far from being unhappy … small things can make you sad or shift your balance and I think this is what happened."
Klas believes his son was too stressed by his demanding musical career.
Speaking at CNN, he said: "As a DJ or artist you have to do a lot of things you don't want to do, in the end that takes a part of you. [It] takes a lot from these people – the journey, the waiting in airports, in the late nights. He began to feel that he wasn't feeling well when he went up there. "
The family of Avicii published his latest album, "TIM", posthumously last month, and the proceeds from the album will go to the Tim Bergling Foundation which was created in the memory of the DJ to support those who have problems with their mental health.