Two “exceptional” bottles of 50-year-old Glenfiddich whisky are expected to fetch tens of thousands of pounds when they go under the hammer in Edinburgh.

The pair of whisky bottles, said to have an aroma of tobacco leaf and orange marmalade, have an estimated value of £13,000 to £15,000 each.

They are the star attraction at Bonhams whisky sale in Edinburgh on March 7.

In 1991, 500 bottles of Glenfiddich from casks filled in 1937 and 1939 were released.

Bottle number 250 and 449 from the batch are being auctioned off. They are said to have "a complex nose with floral notes, tobacco leaf and a hint of smoke and an initial taste of orange marmalade and vanilla toffee followed by aromatic herbs, soft fruits, and gentle smoke".

Martin Green, Bonhams whisky specialist, said: "The Glenfiddich 50 year old is regarded as one of the truly great achievements in whisky making, and bottles from the 1991 release are very highly sought after.

"I was lucky enough to be at the launch and to have tasted the whisky then and it is easy to appreciate why it has such a high reputation."

Also under the hammer is a bottle of The Macallan-52 year old, distilled in 1950 and bottled by hand in 2002. It is estimated to fetch between £5000 - £7000.

A Bowmore-40 year old, distilled in 1955 and bottled in 1995 in a Caithness Crystal decanter, is also expected to make between £5000-7000.