Almost $1.5m of bitcoins formerly held by cryptocurrency exchange Moolah have gone missing, after the exchange declared bankruptcy. The cash is believed to be in the personal wallet of the company’s founder and chief executive, Alex Green, who has not been heard from since Moolah went bust.

In the last public communication from Green on 19 October, he revealed that he was previously known as Ryan Kennedy until a name change by deed poll “in an attempt to start my life over and have some peace”.

As Kennedy, he had gained notoriety among communities including British fans of anime Japanese cartoons, as well as bitcoin investors, for a series of failed business ventures including Flirble, a web hosting service that ran for two months and Lemon, a bitcoin mining firm that shut down in 2013.

Others had linked him to the names Ryan Albright, Ryan Fletcher and Ryan Gentle before he disappeared and re-emerged at the beginning of this year to start bitcoin exchange Moolah as Alex Green.

The final saga started in July 2014, when a rival to Moolah, called Mintpal, was the target of a hack which lost it $2m of bitcoin. Green and three others bought Mintpal a few weeks later, and integrated 70,000 accounts at the exchange into Moolah.

But on Sunday, Alex Green went public in a blogpost with his former name, and admitted that Moopay – the parent company of Moolah – “is now insolvent”. He blamed the insolvency on a bug in the software which “seems to have manifested as people being able to arbitrarily double their balances on a whim”, but said that former users of MintPal “had not been subject to the same exploit”.

He ended the post saying that “I know sorry isn’t good enough. I know I have fucked up on a catastrophic level. There should have been better procedures in place.” Green has not been heard from since.

But the MintPal users, who were assured that their money was safe, are getting concerned. Their accounts are still locked, and due to the open nature of the bitcoin system, it’s possible to see exactly where the money has ended up: $1.43m of it has flowed into and then out of one specific account, which one of the other three investors in MintPal says is under the control of Green himself.

We do not know Ryan's current location, and he is unfortunately the only one with access to customer funds. — MintPal (@MintPalExchange) October 19, 2014

Already, users are banding together in an attempt to trace where the bitcoins end up. But currently the case is reminiscent of the digital wild goose chase that ensued after online black market Sheep shut down. Then, the founder ran off with over 5,000 bitcoins, and users dutifully traced the money through the network – until they realised that what looked like dastardly attempts to evade them were actually just the inner workings of a bitcoin exchange; the crook in question had sold the bitcoins days before.

Even before Green came clean, questions had been raised about his identity. Moolah was a small player in the bitcoin market, but almost dominated the smaller meme-based cryptocurrency Dogecoin. That community had watched as the company ploughed money and marketing into Dogecoin, even becoming the main backer of a successful attempt to sponsor a Nascar racer, and had wondered why Green had zero online footprint – a rarity for the digitally savvy.

In July, a week before Mintpal would be hacked, the Daily Dot accused Green of a litany of questionable business practices.

“That no one outside of Moolah had ever seen [Green’s] face became such an established theme,” wrote Kevin Collier, “that the company’s COO, Landon Merrill, jokingly tweeted a ‘picture’ of Green: a person wearing a cardboard box on his head. Moolah’s location repeatedly changed, too. The company was registered with a Swiss address, then Moolah announced plans to create a physical office in Ireland, then in England.”

The Guardian has attempted to contact Green using his last known details, but has received no reply.