The Bistamp website, ranked the third biggest exchange of the digital currency in the world, was launched completely anew after the hackers attacked it Sunday, stealing some 19,000 bitcoins with a market value of around EUR 4.3m in the process.

An investigation has been launched by the exchange and authorities into the attack and features computer forensic experts, Kodrič said in a statement posted on bitstamp.net site late on Friday.

The subsequent efforts to relaunch the online exchange have resulted in beefing up of security measures for the site.

Bitstamp was launched in 2011 by Kodrič and Damijan Merlak, who subsequently moved its operations to London.

In the immediate aftermath of the collapse of the Japan-based Mt Gox exchange in April of 2014, it ranked as the world's biggest exchange of the digital currency, but has been overtaken in recent months.

In the last month its market share among bitcoin exchanges stood around 6%, good for third place in the world.