Jacinda Cambray was enjoying her  ‘sweet 16 party’ with around 40 guests when they were subjected to the unexpected brown shower at Levittown, Pennsylvania. Fortunately a specially-erected canopy spared most of the partygoers from being plastered with human excrement.

“Out of nowhere from the sky comes a bunch of faeces, lands hard on the canopy,” said the girl’s stepfather, Joe Cambray, talking to Fox 29 Philadelphia. “It looked a hundred birds flew over and went to the bathroom simultaneously.”

Mr Cambray’s sister, Kristie Rogy, said the incident was plane disgusting: “We’d just gotten done with the cake, thank God, because within two minutes something fell from the sky. It was brown. It was everywhere. It got on everything – it was gross.”

The family are convinced that a party-pooping aircraft flying thousands of feet overhead was responsible for the deluge of dung – and have filed a complaint with the Federal Aviation Administration. Five aircraft have been earmarked as potential suspects, and the unsavoury incident is now being investigated as all planes are required by law to dump waste an airport.

However, similar incidents are far from unknown. British woman Caroline Guy claimed in 2013 that a block of frozen waste had crashed through the roof of her caravan in Staffordshire, and last year New Zealander Karen Bass said her house in Auckland had been showered with waste from an aeroplane. The country’s civil aviation administration subsequently blamed the mess on ducks.