Almost 30,000 bitcoins were auctioned on Monday, with a combined value of almost $20m, but the buyers remain elusive

Almost 30,000 bitcoins seized from the Silk Road, the defunct darknet market, were auctioned on Monday by the US Marshals Service.

The USMS has revealed that 45 bidders registered, each putting down a deposit of $200,000, and that 63 bids were received. The process was carried out as a blind auction. No winning bidder has come forward, and the USMS didn't release any information about the winners, or the price they eventually paid for thousands of bitcoin.

In October 2013, the US government came into possession of the bitcoins when it arrested San Franciscan Ross Ulbricht, now 30, and charged him with running the Silk Road, an online black market.

One of the bidders was bitcoin-based consumer finance startup Circle.

Speaking to the Guardian before the results were announced, the company's CEO and co-founder, former Macromedia CTO Jeremy Allaire, said that the mere existence of the auction was likely to be a boon for the currency.

"I think it's a very legitimising activity. The fact that the federal government of the United States is saying 'this is a legal asset, and we're going to liquidate it like other financial assets' is a big deal."

Allaire, who declined to comment on the details of Circle's bid, added that "as a company who has a treasury and a set of reserves in Bitcoin … for us it's just an opportunity to acquire a meaningful chunk of bitcoin, potentially at a discount to spot prices, and to do that without affecting the price.

"If we were to go out to [bitcoin exchange] Bitstamp and trade for a whole bunch, it's going to move the price upward. So just from a pure economic calculus, it's a good opportunity."

While no winners have come forward, many bidders have revealed that they failed to secure the bitcoins. Alan Silbert, founder and CEO of online bitcoin luxury marketplace BitPremier, estimated that $20m worth of bids went unsatisfied, and that those bidders may now try and fulfil their demand on the open market. Since the auction closed, the price of bitcoin has climbed to $651, up from $570 when it began, which could indicate Silbert's prediction coming to pass.

Other bidders entered the auction in syndicates. Investment firm SecondMarket received 186 bids from 42 bidders, but said it was outbid on all blocks, while Pantera Bitcoin's syndicate also failed to get hold of any bitcoin.

But some have questioned whether reports from the bidders are to be trusted. Isabella Kaminska, writing in the Financial Times, pointed out that the individuals and companies reporting on failed bids "may have an interest in proclaiming that their bids were unsuccessful or that the accepted bids were higher than expected (even if they they were not)."

Writing later on her own blog, Kaminska went further, suggesting that "the whole auction was a sting."

"For, if I was the government stuck with a bunch of bitcoin I couldn’t shift because everyone knew my coins were the Silk Road batch, I too might be inclined to “launder” the association away via a sealed auction that would make everyone assume that the coins were no longer on my book but actually still were," Kaminska said.

"Especially if the process also provided me with great information about prospective bidders. Much easier than buying stock in the market directly in any case."

• US government prepares to auction $17m of seized Silk Road bitcoins