Big Mac special sauce being auctioned for $18,000

SYDNEY, Feb. 2 (UPI) -- A bottle of the Big Mac secret sauce is up for auction in Australia and already receiving more than $18,000 in bids.

There are still eight days left in the auction.

"Big Mac sauce is one of the most iconic McDonald's ingredients and people often ask us where they can buy it; so we're excited to be the first country in the world to offer tubs of Big Mac sauce to our customers," said McDonald's Australia's Chief Marketing Officer Mark Lollback.

There will be 600 25-ml bottles of the sauce sold at locations across the country. Proceeds will benefit the Ronald McDonald House charity in Australia.