The Baggy Green, made with 100 per cent local wool, is quite possibly the most recognisable and treasured piece of Australian sporting equipment.
Yet a number of eBay sellers, all hailing from India, are now offering "rare and authentic" Baggy Green caps for as little as $8.99.
''I'm very surprised and very disappointed to see that,'' CA spokesman Peter Young told Fairfax Media.
''We are vigilant about this kind of thing.
''It's important we let the world know we do protect Cricket Australia's intellectual property vigorously. We take this kind of issue very seriously and the matter has been referred to our legal department.
''We regard the cap as an iconic symbol and we protect it very, very closely. It is one of the most powerful symbols in not only Australian cricket, but world cricket.
''Genuine baggy green caps, when they go to auction, do very well. In one case, one went for over $400,000 because it was a Sir Donald Bradman cap.''
Originally the Baggy Green was issued as part of the uniform in your kit bag and be replaced on each tour, but then in the early 90s an unofficial tradition kicked off where players would hold on to the original woollen cap and wear it for their entire career.
Former Australian captain Mark Taylor, cap number 346, started the tradition of presenting the Baggy Green to the debutant on the first day of the Test during his tenure.
Steve Waugh, cap 355, then developed that tradition by inviting past players to come back and do the presentation, while Ricky Ponting often made the presentation himself as captain.
Since 1877, 437 caps have been issued, the most recent to Alex Doolan in South Africa.
Quick Single: Doolan receives Baggy Green 437
One thing current and former Australian players agree on it is a very emotional moment in your career.
"The first time I put a Baggy Green on it was very emotional," Mike Hussey told cricket.com.au.
"It was the culmination of 10 years of cricket and a lot of hard yakka; a lot of ups and downs and heartache and all of those emotions coming together to get your ultimate dream. Growing up that’s what I dreamed of wearing."
"You sort of pinch yourself to say this is actually mine now," Ryan Harris added.
"Justin Langer said a good thing to me. He said you're not looking at his Baggy Green and touching his Baggy Green, it's your Baggy Green now. That sort of stuck with me and it's quite an amazing feeling."
"It's a wonderful club to be involved with only 400-odd having had the opportunity," said Brett Lee. "It's my most prized possession."