These items headed for India after an auction yesterday failed to capture local interest, including from the Bradman Museum.
The items, among which were Bradman's 1946 baggy green cap and the bat he used to score 234 in a world record fifth wicket 405-run partnership with Sid Barnes - who also scored 234 - were sold to the Indian buyer who was not identified.
"It's very disappointing that the top items, including three match-used bats and a Test cap, received absolutely zero interest from our local Bradman Museum, to the point where they couldn't even be bothered coming over to view bats that had never been documented or to see items of historic importance," Tom Thompson of Ravenswick Auctions, said.
The 1946 bat was expected to attract up to 120,000 dollars but was referred to the buyer at 65,000 dollars. The baggy green cap was expected to fetch up to 180,000 dollars but sold for 100,000 dollars, Sydney Morning Herald reported.
Other items included a bat used by Bradman on a tour of Canada and the US - known as the 'Honeymoon Tour' as it followed soon after his marriage to Jessie Menzies - that was expected to attract about 15,000 dollars but sold for 8000 dollars.
And a bat Bradman used for New South Wales and South Australia went for 10,000 dollars, about half what was expected.
"The disappointment is that there weren't enough people here and the so-called institution, the Bradman Museum, failed to even sight the things let alone engage with them," Thompson said.
Bradman Foundation executive director Rina Hore said that representatives of the museum (now known as the International Cricket Hall of Fame) had viewed the items from the collection of collector Chris Moyle in June.
However, independent valuation had priced the key pieces beyond the museum's reach.
"I'm not quite sure why [Thompson] is disappointed. I'm not quite sure why he expected that we'd turn up," Hore said.
"Would we like a benefactor to have bought them and given them to the museum? Of course we would. But we just felt that when they were offered to us we weren't in a position to secure them."
"It is unfortunate that items like these go out of the country. But there are fabulous collectors and benefactors here who have purchased items and lent them to the museum to make sure we keep a good part of this history in the country."
Donald George Bradman, often referred to as "The Don", was an Australian cricketer, widely acknowledged as the greatest Test batsman of all time. Bradman's career Test batting average of 99.94 is often cited as statistically the greatest achievement by any sportsman in any major sport.
He died in 2001 at the age of 92.