Fifty Shades Of Grey director Sam Taylor-Johnson was left red-faced after police turned up at her home when a passer-by spotted a gun on a desk inside.
The gun, a deactivated M16 assault rifle, had been given to the film-maker and photographer as part of an art project and she was due to auction it off for charity at Bonhams on October 17.
But a Metropolitan Police spokesman said firearms officers attended the north London address, where she lives with her actor husband Aaron Taylor-Johnson, shortly before midnight last night.
A spokeswoman for the couple said: "We can confirm that early this morning police were called to the London home of Mr and Mrs Taylor-Johnson following a report of a firearm on the premises by a concerned passer-by.
"The family were not present in the property at the time but the police gained entry via a key holder.
"The firearm was located in Sam Taylor-Johnson's basement studio and has been confirmed as a certified and fully decommissioned M16 assault rifle that was provided to Mrs Taylor-Johnson by the international charity Peace One Day as part of an art project entitled 'Peace One Day M16'."
And Taylor-Johnson is not the first celebrity to have sparked a police raid in the same way.
Armed cops turned up at Spaced actor Nick Frost's door when he was playing Territorial Army obsessive Mike in the Channel 4 comedy, when he took a gun home to practise a scene.
He said: "My voice went very high and I said, 'I'm an actor!' I was told later that they had blocked the road off and had a sniper. If I had pointed the gun at them, they would have shot me!"