Beyonce, Jennifer Lopez and Barnoldswick worker Graham Butterfield all have something in common.

For Graham and the A-list stars all have posteriors worth a cool £1 million.

Fifty-four-year-old Graham has such a sensitive bottom that he has been promoted to the position of bed bouncer at Barnoldswick bed maker Silentnight, and the company has taken out £1 million insurance on his asset.

Graham, a father-of- two, has worked at the Long Ing Lane factory for 27 years.

However, it was only recently that bosses discovered his behind was more responsive than the norm.

In fact, his hypersensitive rear was so reliable when it came to recognising different fillings in the Silentnight mattresses that he began to be consulted when designers started working on new products.

His new role of bed bouncer involves jumping up and down on the beds and giving feedback on their softness, textures and fillings.

Graham's bottom can ultimately decide whether a bed goes to market or back to the drawing board.

He said: "It may sound ridiculous, but my bottom really isn't like any other.

"I have increased sensitivity around the buttocks and can literally feel the difference in materials and fillings used, simply by sitting on it.

"However, I was amazed to have such a high price placed on what I do.

"I'm sure I'm the butt of everyone's jokes, but I'm very proud to be the owner of a £1 million backside." Graham first began taking an interest in the different materials used for the mattresses 10 years ago.

But his feedback was so insightful that his sensitive bottom became company folklore and the product testing team gradually began to consult him on each new product.

Graham said: "It started off as a bit of a joke and we still have fun with it at work, but it has also become a serious business. I just want to make sure the beds we make are as comfortable as possible."

Graham, who lives in Oakworth, doesn't follow any special regimes to keep his rear in peak condition.

He said: "All I need is a comfy chair. It's not like I spend my time sitting on a rubber ring. I'm just naturally sensitive, although most people think that Yorkshire men are insensitive."

Steven Simpson, brand manager at Silentnight, said that Graham's derriere was worth its price tag.

Mr Simpson said: "Silentnight is so committed to comfort we're convinced taking out this £1 million insurance policy is worth every penny."

Insurance company Zurich said that it was rare to be asked to provide such specific cover to this type of customer, but it would ensure that "should the worst happen the company will be compensated for the loss of his undoubted expertise".