​Mt Gox chief was suspected as Silk Road operator

It has been revealed during the trial of alleged Silk Road operator Ross Ulbricht that the CEO of failed bitcoin exchange Mt Gox, Mark Karpeles, had been suspected of being behind the online black market site, according to reports.

Mt Gox CEO Mark Karpeles was investigated by the United States Department of Homeland Security (DHS) under suspicion of being behind the Silk Road marketplace, it has been revealed during the trial in New York of alleged Silk Road operator Ross Ulbricht.

Department of Homeland Security special agent Jared Der-Yeghiayan said under cross examination on Thursday that from 2012, there were "bits and pieces" of evidence that led him to believe that Karpeles and associate Ashley Barr were behind Silk Road, according to the UK's Financial Times.

The revelation comes as Ulbricht's defence team, led by his lawyer Joshua Dratel, works to convince the jury that although Ulbricht founded Silk Road, he was not Dread Pirate Roberts (DPR) -- the online alias used by the site's operator -- but rather the fall guy for others who had taken on the site.

According to Der-Yeghiayan, it was not until September 2013 that Ulbricht came under his suspicions.

Forbes' Sarah Jeong, who along with other members of the media has been following the case from inside the courtroom, tweeted on Thursday that "the DHS agent's theory was that Karpeles operated Silk Road to drive up the price of bitcoin".

She also wrote that the "DHS agent admits that he himself at one point in the investigation thought there were multiple DPRs", and that the "DHS agent acknowledged under cross [examination] that he was preparing an affidavit for a warrant to search Karpeles's email".

Reports indicate that the DHS agent's theory around early to mid-2013 was that the bitcoin exchange worked in tandem with Silk Road, and that investigations found that Mt Gox subsidiary and Karpeles' holding company Mutum Sigilum had registered the domain silkroadmarket.org.

Tokyo-based Mt Gox shut down without warning in February last year. The bitcoin exchange, once one of the most popular platforms online, filed for bankruptcy later in the same month.

At the time, $500 million worth of bitcoin, belonging both to the exchange and users, vanished.

Earlier this month, it emerged that the spectacular collapse of Mt Gox could have been an inside job, with Japanese police saying that they believe the majority of bitcoin stolen from Mt Gox was due to insider tampering.

Ulbricht's trial will resume on Tuesday.