Acting judge Nigel Rein, handing down his judgment today, ruled against Thomas and ordered him to hand over the plane for the agreed amount. The date of the handover will be decided next week.

"It follows that, in my view, a binding contract was formed between the plaintiff and the defendent and that it should be specifically enforced," Justice Rein said in his decision.

The judgment sets a precedent for future cases and means eBay sales could now be legally binding. A judge had last year ruled the plane could not be moved from its hangar in Albury until the dispute was settled.

Smythe, an Adelaide war-plane enthusiast, was the only person to bid on the item, matching the $150,000 reserve price just seconds before the auction ended in August last year. But Thomas, a radilologist from Albury, had already agreed to sell the plane to someone else for $100,000 more than Smythe's offer. Smythe took him to court hoping a judge would force Thomas to follow through with the sale.

Before the ruling was handed down, eBay spokesman Daniel Feiler was adamant that any decision would have no impact on public confidence in the auction site. "It has always been our understanding that you are entering into a binding contract when you are listing an item and someone has made a bid on the item," he said, but added real estate sales were an exception because bids on houses were only expressions of interest. "If someone has a repeated behaviour of not purchasing or refusing to sell the item once the thing has ended, normally we'll reach out and educate them in the first instance but if they then show a repeated habit of not fulfilling their commitments then they get suspended from the site," he said.

Feiler added eBay sellers had the option to reject any bids before an auction closed and encouraged both buyers and sellers to examine feedback history before proceeding with a transaction. eBay has 5 million Australian members and 17,000 of those make their primary living from selling there, according to ACNielsen.

The Temora Aviation Museum, which houses its own Wirraway plane, said a total of 755 were built in Australia between 1939 and 1946. A spokeswoman for the museum said she had not seen the plane referred to in this case but estimated it was worth around $250,000.