Hamilton Hall, which overlooks the 18th green of the famous Old Course in St Andrews, was recently put up for re-sale with a multi-million-pound price tag after its American timeshare developer was hit by the recession.
The preferred bidder has been named as Herb Kohler, the US tycoon who owns the landmark Old Course Hotel in the town.
But one of the failed bidders has lodged a complaint with the Royal Incorporation of Chartered Surveyors (RICS), alleging the company that handled the bids failed to follow the proper process.
Paris-based golf course consultant Richard Wax claims the selling agents broke rules over due diligence set out in the RICS guidelines. The complaint is now being investigated and could delay the sale.
Mr Wax claims all the bidders should have been invited to present their proposals in person before a decision was made on a preferred bidder.
He also claimed that other bidders were not given the chance to "update" their bids before a preferred buyer was announced.
Selling agents Jones Lang Lasalle strongly denied the claims.
In its heyday as the Grand Hotel, the 114-year-old landmark, known as Old Red, catered to the likes of Edward VIII, George VI and Rudyard Kipling. But Hamilton Hall has lain empty and derelict since the collapse of an 85 million scheme to convert it into an ultra-exclusive timeshare aimed at the world's wealthiest golfing enthusiasts.
In June, it was put up for sale by the Bank of Scotland, which repossessed the building, and nine multi-million bids were made to the selling agents Jones Lang LaSalle.
Jason Hogg, development director at Jones Lang LaSalle, said: "We have not received any notice from the RICS that a formal complaint is being investigated.
"The sale of Hamilton Hall was dealt with professionally and in the best interests of our client."
Mr Wax, chairman of Golf Surveys Ltd, had planned to convert the building into a golf-themed conference centre and visitor centre, including a cinema, bars and public spaces devoted to the sport.
He said he had received confirmation from RICS that an investigation was now under way after he complained about the process.
He said: "This process of selling Hamilton Hall is quite rightly being investigated by the RICS.
"It now looks like the Bank of Scotland is going to sell the building to the highest bidder, regardless of what would be best for golf, best for St Andrews and best for Scotland.
"We believe that due diligence was not followed during the sale process and that needs to be properly investigated."
RICS refused to confirm any details of the investigation. However, The Scotsman has seen a letter from RICS, confirming Mr Wax's complaint is under review.
The last buyer, Wasserman Real Estate Capital, had secured planning consent to convert the listed building into 23 luxury timeshare apartments. But construction was put on hold when the property market crashed and it was soon repossessed.
Toilet tycoon with an eye for the finer things in life
HERB Kohler has made billions from toilets. He is the chief executive of the Kohler Company, which makes a large proportion of the world's bathroom fixtures. A love of golf led him to St Andrews.
The Kohler family is the most powerful in Wisconsin, the state they helped build. The Kohler Company was founded in 1873 by a 29-year-old Austrian immigrant named John Michael Kohler, Herb Kohler's grandfather.
Walter J Kohler took over the company in 1905 and oversaw the construction of the planned village of Kohler and the American Club, a dormitory for the company's immigrant artisans and craftsmen, which is now a five-star resort hotel.
Herb Kohler, a 70-year-old remarried father of three, succeeded his father as Kohler Company chief executive in 1972. A keen horseman, Mr Kohler also runs a successful stud farm and enjoyed a small role in the Kevin Costner western Open Range.
He bought the Old Course Hotel in 2004 for about 40 million and invested a further 20m to refurbish it, including a jazz club reportedly at the suggestion of Prince William, whom he met while the heir to the throne was a student at St Andrews. In 2007, his net worth was estimated at $4 billion but is believed to have dropped to $1.5bn.