TWO thugs are behind bars after carrying out a terrifying £500k armed robbery at Gleneagles Hotel that left staff and guests fleeing for their lives.

Career criminals Richard Fleming, 42, and Liam Richardson, 30, were part of a three-man gang who carried out the shocking heist armed with hammers, a machete and a pistol at the posh resort in Perthshire, Scotland.

The gang stormed the five-star hotel complex in June last year, pointing a gun at staff before stealing a huge haul of high-value Rolex watches from a jewellery store within the resort.

Today, London hood Fleming was found guilty over his involvement in the raid following a trial at the High Court in Edinburgh.

Accomplice Liam Richardson had already pled guilty to his part in the robbery.

The pair will be sentenced next month.

The gang - armed with hammers, a machete, and a pistol - smashed display cabinets and made off with Rolex watches from jewellers Mappin & Webb.

Jewellery salesman Daniel Horne, 54, said he feared terrorists had launched a killing spree.

He told the court: “I heard bangs and said to my colleague, ‘That sounds like gunfire’.

“I thought they were killing people. I thought it was a terrorist attack.”

Fleming had admitted casing the hotel weeks earlier but denied being involved in the theft.

The gang swiped more than £500,000 in the heist from Gleneagles Hotel

Prosecutor Jane Farquharson rubbished Fleming's claim that he was buying drugs in Glasgow during the raid at Gleneagles.

She told the High Court in Edinburgh: “I would suggest that is inherently unreliable.”

Cops discovered Fleming, 42, was among a three-man gang after a “painstaking and meticulous” investigation, headed by detective chief inspector Andrew Patrick.

He said: "Staff and witnesses going about their business thought what they had witnessed was a terrorist attack given the threat level at that moment in time.

"It was very quickly evident it wasn't a terror attack.

"But that's how the people going about the foyer described it to us.

"People dropped to the floor when they saw people run in with firearms and knives.

"It was the innocent members of the public there who thought there was going to be a terror attack.

"If you saw the level of violence there's no exaggeration to think you were about to be part of or witness a terror attack."