TOKYO: Bitcoin prices suffered a dramatic plunge on Friday, dropping 20 percent at one point towards the $13,000-mark in volatile Asian trading.

The cryptocurrency kicked the week off with a bang, almost hitting $20,000 as it extended its astonishing rise but it has suffered a significant correction this week, losing a third of its value.

Bitcoin dropped to $13,048 briefly from around $16,500 in late trading on Thursday, according to data compiled by Bloomberg.

At its height, Bitcoin had soared almost 30-fold since the start of the year and has moved into the mainstream as two major US exchanges began trading futures in the unit.

However, it took a 15-percent hit on Wednesday following news that a South Korean exchange had been hacked and experts say it is experiencing a long-overdue correction.

Bank of Japan Governor Haruhiko Kuroda said on Thursday that the price surge of the virtual currency was "abnormal".

The vice-president of the European Central Bank has also expressed concern about the relentless rise in the value of Bitcoin and the potential risk accompanying the trend.

US Federal Reserve boss Janet Yellen has said Bitcoin is not money and called on banks to be certain their digital currency transactions adhere to anti-money laundering statutes.