Alan Sugar DOES have a booster seat and we've got the picture to prove it

But in The Apprentice, Sir Alan Sugar is apparently given help to take the high ground over contestants.

Unknown to millions of BBC1 viewers, he has been using a makeshift wooden plinth which increases his seated height by at least three inches.

Booster seat: Blocks and a platform raise Sir Alan on his lofty position for TV's The Apprentice

You're highered!: Flanked by his lieutenants, Sir Alan interrogates a contestant on The Apprentice from his tall chair

It means he has a more commanding presence when grilling wannabe employees about the business challenges he has set them.

The measures were perhaps adopted after producers realised the 5ft 6in tycoon's famous boardroom tirades might not have quite the same effect if he was dwarfed by the contestants and by Nick Hewer and Margaret Mountford, his lieutenants who sit either side.

The current series has seen an unusually large number of tall male entrants, including Lee McQueen and Alex Wotherspoon – who are both well over 6ft.

The height booster is fixed under 61-year-old Sir Alan's chair when filming the boardroom scenes.

There, he is heard lambasting contestants for failing their challenges and ultimately yelling at one unfortunate soul: "You're fired!"

The platform – a 3ft square inch thick board – stands on inch-thick lifts at its four corners.

On top of the platform, further inch-thick blocks support every one of the five legs on Sir Alan's swivel chair.

Contestant Jenny Celerier was first to notice something was afoot after being fired two weeks ago.

She said at the time: "I did notice when he got on his chair he did do a sort of little jump to get on it."

Producers are careful to film Sir Alan only across the table, where he appears slightly higher than his two sidekicks.

But the show's editors this week missed a split second shot which revealed the platform.

The device was noticed by staff at Virgin Radio, who quizzed contestants about it after they left the show.

A spokesman for The Apprentice insisted the platform is not there to boost Sir Alan's height, but to hold his chair in place.

"Being a swivel chair, there is a wooden frame, bolted to the floor into which the five wheels are sunk – to anchor it for camera positions."