Pop diva Madonna's 14 never-heard-before songs, reportedly recorded for her upcoming 13th album Rebel Heart, have leaked online.

The songs leaked on Tuesday night, December 23. Madonna took to Instagram to express her displeasure over the leak, reported Aceshowbiz.

The tracks that unexpectedly hit the internet included Veni Vidi Vici, Beautiful Scars, Freedom, God is Love, Hold Tight, Best Night and a collaboration with super-producer Pharrell Williams called Back That Up (Do It).

"Real Rebels think for themselves! Real Rebels respect ART! Real Rebels are Rebels in their rebelheart," she wrote, captioning her upcoming album's cover art.

The 56-year-old singer posted the Christmas version of the artwork and wrote, "Santa came early this year! good things come to those who wait!"

Earlier this month, a few 'unfinished' songs allegedly also created for 'Rebel Heart' surfaced online without her consent.

She vented her anger, saying that the leak was 'artistic rape' and 'a form of terrorism'. The 'Material Girl' hitmaker then made her album available for pre-order and released six new songs on iTunes. She thanked fans who chose not to listen to the leaks.

(Outlook)