A contestant on Who Wants To Be A Millionaire has stunned viewers with the surprising reason why he knew the answer to the £125,000 prize question.

Things were heating up in the ITV studio as the contestant was quickly climbing the board towards the million-pound prize, with host Jeremy Clarkson turning to him to say: "You've got no lifelines left now. We're getting into the sort of territory with wife changing winnings... I mean life, sorry, I mean life.

"This is heading for six-figure territory."

ITV

At this point it's clear the contestant is wondering if he's made a mistake by agreeing to continue instead of walking away with the £64,000 he'd already secured. I'd be thinking the same, to be fair.

Clarkson then asks the make-or-break question, turning to him saying: "The ruins of Urquhart Castle stand on the banks of which loch?" before reading the multiple choice answers: "Loch Lomond. Loch Ness. Loch Broom. Or Loch Maree."

The contestant gives a wry smile as if to say he knows this one and pauses before 'loching' in (sorry, bad joke) his answer.

ITV

He fills in the anticipating crowd on his secret by saying: "I know this, and I know this because I lost my leg there."

The crowd gasp as he says: "Not at the castle, chill out," to which they erupt with laughter.

"If I remember rightly, on the loch - and I wasn't there long, so I couldn't tell you - there's a little inlet with a castle's ruins there. So...Kismet, I'll go Loch Ness."

Safe to say, Clarkson looked astounded by the revelation.

"I don't know if my wife would kill me if I lost this much money. Loch Ness, final answer," the contestant adds.

After what feels like an eternity, Clarkson turns to the lucky punter and says: "You've just won £125,000," to which the room fills with applause.

ITV

The man went on to explain how he had a crash on the day he visited Loch Ness, so the memory has stuck with him and turned out to be, in this case, a stroke of luck.

What are the chances, aye?