Bitcoin dropped to the lowest level this year as pressure mounts on the embryonic digital currency sector, with global central bankers raising questions of viability and government regulators increasing scrutiny.

The biggest virtual currency fell as much as 5.2% to US$5 825.10 on Sunday, piercing the previous low of the year of $5 920.72 that was set on 6 February, according Bitstamp prices. That bought its decline from the record high of almost $20 000 reached in December to 70%.

On Friday, Japan’s Financial Services Agency ordered six of the country’s biggest crypto trading venues to improve measures to prevent money laundering. The companies must submit their plans by 23 July. New pressure in Japan, one of the most crypto-friendly jurisdictions, demonstrated the market’s fragility to regulatory moves in the absence of much positive news.

Peer-to-peer money also came under fresh pressure in recent weeks after two South Korean exchanges said they were hacked. That raised fresh concerns about the security of investor holdings. India’s central bank gave commercial lenders until early July to stop providing services with any company dealing with digital coins, in an order that’s reportedly being challenged in courts.

Bitcoin was down 4.9% on Sunday as of 11.47am in New York. Bitstamp is one of the major price sources for cryptocurrencies, which have no unified quotation system and can vary substantially among countries.