Eagle-eyed customers have blasted Paul Hollywood after accusing his flagship bakery of selling sausage rolls by the inch illegally - because it's an imperial and not a metric measurement.

Bemused shoppers questioned if the 52-year-old Great British Bake Off judge's Knead bakery in Euston station in central London was flouting retail law by flogging the meat treats in the old-fashioned imperial measure after spotting the unusual sales method.

The Weights and Measures Act states that with a few exceptions such as pints for beer and milk, food and drink can only be sold in metric measurements, such as centimeters and millimeters.

Paul Hollywood (pictured) has come under fire for his bakery selling sausage rolls by the inch. Selling products by imperial weight only is illegal under the Weighs and Measures Act because most food and drink must be sold in metric weight with a few exceptions

A spokesman for the Department of Business, Energy and Industrial Strategy, confirmed that the transaction of selling portions of sausage roll by the inch flouts the law.

He said: 'You can label a sausage roll, or in fact almost any other product, in imperial measures, but when you're selling the product on the basis of measurement you should always include metric.'

Though it is legal to display the imperial weight, the transaction must take place in metric weight and an imperial measure can not be more prominent than the metric equivalent, according to the law.

Diners flagged the irregularity on social media after spotting posters advertising the unusual way of selling sausage rolls, including at a branch at Euston station in central London.

A visit to the outlet yesterday showed that no metric equivalents appeared to be visible.

Paul Hollywood opened his first bakery, Knead Bakery and Coffee, at Euston station

The baker, who shot to fame as a judge on the Great British Bake Off, opened his very first bakery at the central London station last year.

It sells croissants and pastries, pies, muffins, breakfast butties, sandwiches and salads.

But several eagle-eyed shoppers noted his odd way of serving sausage roll, flavours of which include The Original pork sausage and The Boss, a pork and chorizo sausage roll topped with fennel seeds, by the inch.

Paul Reynolds spotted the offending advert and said: 'Seems Paul Hollywood is selling sausage roll by the inch at his cafe at Euston Station. Nice idea and they look delicious, but pretty sure that is illegal?!!'

Another claimed: 'Red Alert: Paul Hollywood is *illegally* peddling sausage roll in imperial measures.'

Twitter users have spotted that Paul Hollywood may be sellin sausages illegally by the inch instead of using a metric measurement

The Weights and Measures Act states that you can display an imperial measurement alongside the metric one, but it mustn't stand out more than the metric.

The only exceptions are draught beer or cider which is sold by the pint, milk in returnable containers by the pint and precious metals, which are sold by the ounce.

Subway sandwiches are famously named after imperial measurements - a Footlong and a six-inch - but this is legal under a loophole in the law which allows products to be described in imperial weight if they are sold at a set price.

Subway sandwiches are not sold by the inch - you cannot order a 13-inch sandwich for example - and therefore the sandwich chain stays within the law.

However as Knead's sausage rolls are sold by the inch, the bakery appears to be flouting these rules.

Paul - who is currently dating former barmaid Summer Monteys-Fullam who is 22 - gushed about opening Knead last year.

He said: 'Knead has been a project I've been working on for some time, and I can't wait for you to come and experience what we have created.

'We have worked really hard to give our customers something different, making sure we use the best possible ingredients and give customers the greatest service. Just wait until you taste the difference in my bacon butties and sausage rolls!'

The selling tactic has also led to great hilarity online.

Another added: 'Can't just buy a sausage roll at @paul.hollywood's pop up in Euston Station. £1 per inch. Glad more things aren't charged by the inch.'

Knead has been widely criticised on TripAdvisor and has earned just 2.5 stars thanks to dozens of withering reviews. One disgruntled customer said it served 'the worst food in the south of England'.

Representatives for Hollywood refused to comment.