Police in Australia have launched an internal investigation after Lily Allen posted a photo of herself being handcuffed by officers.

The 29-year-old singer asked one of them to do it ahead of her performance at a festival near Byron Bay. 

An image of her kneeling on the ground, head bowed and handcuffed was then put on Instagram and Twitter.

However, the mocked image "breached protocol" and was swiftly removed.

The Australian Federal Police said the officer who cuffed her had breached protocol and was facing "internal processes".

Allen and her team have not made any comment on the matter.