Pop star Rita Ora has sparked rumours she has taken revenge on her ex-boyfriend Calvin Harris by penning vicious lyrics about a former lover in a new song.

She wrote the song "Poison" after splitting from the Scottish DJ, and she was determined not to hold back, comparing her ex to the devil, reports contactmusic.com.

The lyrics include expressions like - "Like a serpent/From the Garden of Eden/You are like poison/Running in my blood" and "I open up my windows/I'm so sick of breathing/Every day I'm trying/But I don't remember who I was before you came."

Ora has not confirmed anything, but fans are speculating the mystery man in the lyrics is Harris.

Ora split from Harris in June this year. She previously dated Kim Kardashian's younger brother Rob, and has recently been linked to fashion designer Tommy Hilfiger's son, Ricky Hil.