Investing.com - Russia will block access to websites of exchanges that offer cryptocurrencies such as Bitcoin, the central bank’s First Deputy Governor Sergei Shvetsov said on Tuesday.Shvetsov said authorities cannot give direct and easy access to such “dubious instruments” for retail investors.He made the remarks at a conference on financial market derivatives.Shvetsov said the central bank sees rising interest in crypto-currencies because of high returns from buying into such instruments.He warned, however, that crypto-currencies gradually transform into high-yielding assets from being a mean of payment.Bitcoin’s price is up 600% over the past 12 months, and 1,600% in the past 24 months is currently trading at around $4,800.00.