A UK cryptocurrency startup that raised $40m (£30m) has been hit by a cyber attack that has shut investors out of their accounts for several days.
Electroneum, which offers a digital currency that can be mined using smartphones, was due to launch its website and mobile app last Thursday, having crowdfunded millions of dollars in bitcoin and ether following a so-called "initial coin offering", or ICO.
The Maidstone-based company's website came under a distributed denial of service (DDoS) cyber attack last week, forcing it to delay the full launch of its mobile mining app.
DDoS attacks involve a network of compromised computers, known as a "botnet", which flood a website's servers leaving legitimate traffic unable to get through and making the website vulnerable to hacking.
Electroneum, which claims 140,000 people hold its tokens, has locked down the accounts while it tries to bring its network online safely.
The startup created the Electroneum cryptocurrency, with many users buying the token in the hope it will spike in value following the rise of bitcoin, which is now worth more than $7,000 per coin.
Electroneum made headlines last month after it received the backing of football manager Harry Redknapp ahead of the launch, who claimed he was "proper excited" about the crypto-startup.
Electroneum says its platform will allow "the average guy" to mine cryptocurrency using technology similar to the computer programs that allows tokens like bitcoin or ether to be generated, but which normally takes significant processing power.