Sam Smith gate crashed a house party to steal a cardboard cut out of Katy Perry

Sam Smith made off with a cardboard cut-out of Katy Perry during a recent house party he was not invited to Photo / Getty Images

Sam Smith made off with a cardboard cut-out of Katy Perry during a recent house party in east London.

The Grammy Award-winning singer-songwriter turned up uninvited after a night on the booze and eventually left with a rather unusual souvenir from the party.

A source told The Sun on Sunday newspaper: "Sam was never invited to the party but he heard about it through his pal MNEK, who was also there. Everyone was a bit surprised when he turned up wasted, out of the blue.

Katy Perry. Photo / Supplied

"After about an hour or so he made his exit with a Katy Perry cut-out that the house's owner had used as a decoration. The whole thing was very odd."

Meanwhile, Sam revealed earlier this year that living a healthier lifestyle led to his dramatic weight loss in 2015.

He previously shared: "I've just not eaten like a pig anymore - that's what I'm doing, basically.

"It's very, very difficult. I love food so much so it's a constant battle. It's always going to be a battle but I'm trying my best."

Sam was recently spotted enjoying a picnic with some pals in Hampstead Heath, where he was seen enjoying a bottle of Prosecco with his friends.