According to reports, the 1.53-carat ring was one of two items swallowed by an alleged thief during a robbery at a Crown Family Jewellers store in Brisbane on 29 November.
David Watts reportedly ingested the rings after being cornered by staff, and police consequently had to wait for him to pass the jewellery pieces.
Authorities allegedly threw out the other ring, valued at $35,000, by mistake.
The auction, which is being held on graysonline.com, began on Monday 16 December and will run until 9pm on Monday 23 December.
The platinum ring has a cushion-cut yellow diamond surrounded by white diamonds and proceeds will go to the Leukaemia Foundation of Queensland.
Watts has been charged over the theft.
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