McTear's, one of the oldest independent auction houses in the UK, said the trophy comes with the original box and paperwork from the Scottish Football Museum, confirming its authenticity.

The 21-centimetre wide trophy was estimated to sell for between £9,000 and £12,000.

But on the day it sold for £16,000 before buyer's premium and VAT were added to bring it to £20,600.

The auction house said the buyer wants to remain anonymous.

Also on sale at the Sporting History, Important Trophies, Medals and Jerseys event was a Rangers Hall of Fame Trophy that was posthumously awarded to Davie Cooper - who died in 1995 after suffering a brain haemorrhage aged 39.

Other items in the auction included a rare Rangers programme for a match against Clyde in 1947 and a Coronation Cup Final programme from the clash between Celtic and Newcastle in 1953.

A spokesperson for McTear's said: "This is a remarkable piece of Rangers and Scottish football memorabilia that marks one of the most impressive achievements in the Club's history.

"We have auctioned a number of important Old Firm items over the years, and the nine in a row trophy sits alongside the highest profile pieces that have gone under the hammer.

"The trophy is being sold by a private individual and we are comfortable with both the provenance of the piece and the legitimacy of the ownership."

Rangers did not comment.

Rangers are set to face Greek side Panathinaikos in the second qualifying round of the UEFA Champions League next month.

The match at home on 22 July will mark Russell Martin's first competitive game as the Ibrox-side's head coach, having been appointed earlier this month.