'Trying 2get2 bottom!' ... Cher has suggested her office 'fkd up'.
US singer Cher is "upset" and trying to get to the bottom of why a key to the city of Adelaide she was given in 1990 ended up on eBay, selling for nearly $US100,000.
The appearance of the brass key and an accompanying memorial plaque on the internet auction house offended Adelaide officials, with mayor Stephen Yarwood saying he was "exceptionally disappointed".
"It must be very embarrassing for her if she is selling it because she needs the money," Cr Yarwood said last weekend.
'Embarrassing' ... Cher with Key to the City in Adelaide in 1990.
In a tweet, the diva said she was mystified about it appearing on eBay.
"I'm upset 2 & trying 2get2 bottom! I Think my office fkd up?" she said on Twitter.
The key and engraved plaque were sold by a user called Authentic_Cher who claims to be the musician's new "personal consignor", saying the item was from her home in Malibu, California.
The auction closed late last week after 146 bids from people around the world. The successful buyer paid $US95,900.
Cher, 65, was awarded the key to the city in recognition of her performance at the 1990 formula one grand prix.
The man who presented it to her, former mayor Steve Condous, said he was bitterly disappointed at the sale.
"If she didn't want to keep it she should have returned it back to the city," he said.
Cher has earned both Oscar glory in her acting career and Grammy glory in her musical career, selling more than 100 million records.