Singer Kesha says she never knew if she would be able to release new music following her lengthy court battle with record producer Dr Luke.

The 30-year-old singer wowed fans when she dropped her first single in four years earlier this week, and she says there was a time when releasing "Praying" seemed like an impossible task, reported Daily Star.

"I've been to hell and back and never knew if this day was going to come," Kesha says.

The single tackles Kesha's "severe hopelessness and depression" stemming from legal battle with Dr Luke, whom she claims sexually assaulted her.