Australian Federal Police officers who handcuffed British singer Lily Allen at her request for a photo opportunity are now the subject of an internal review for "breaching protocol".

After a show at Sydney's Hordern Pavilion on Friday night, Allen flew in to the Gold Coast Airport on Sunday to perform as the closing act at the three-day music festival Splendour in the Grass at Byron Bay on Sunday night.

A photograph of the 29-year-old, kneeling on the ground in handcuffs with an AFP officer standing behind her, was uploaded to Allen's Instagram account on Sunday afternoon, alongside the caption #uhoh.

Allen also tweeted the link to her 4.7 million Twitter followers.

The photograph has been deleted from Allen's Instagram account and the Twitter link no longer works.

An Australian Federal Police (AFP) spokesman said Allen had asked officers to place her in handcuffs for the photograph.

"On 27 July, AFP members escorted Ms Lilly Allen as she was transiting through Gold Coast Airport," the spokesman said.

"At her request, the members involved placed open handcuffs on Ms Allen for a photo opportunity.

"It appears the members involved were caught up in the moment and standard protocols were breached.

"This matter is now subject to internal processes."