Bitcoin tumbled to a one-month low on worries that Chinese authorities are going to tighten their oversight of the digital currency.

The price of bitcoin dropped to $759.6 on Thursday, the lowest since Dec 7, after a decline of as much as 16 percent in the previous session. It was trading down 1.6 percent as of 11:50 am in Hong Kong, according to data compiled by Bloomberg. The cryptocurrency hit an all-time high of $1,161.89 on Jan 5.

Officials with the Shanghai branch of the People's Bank of China and the city's finance office conducted an on-site inspection at the BTCC online bitcoin exchange, according to a statement from the PBOC, looking for evidence of violations, such as market manipulation or money laundering, and assessing the safety of customer funds.

BTCC said in a statement it expects to have additional meetings with the regulators this week.

"All operations at BTCC are normal, and we continue to actively work with regulators to ensure that we remain compliant," the exchange said on its website. "In the meantime, we urge our customers to take a rational and cautious view to news articles which speculate on the visit and discussions."

The inspection is raising concern that China may tighten its supervision and control over the country's bitcoin exchanges, which were instrumental in driving up the digital currency in recent weeks.

Increased regulatory scrutiny may damp demand for bitcoin, which had risen as people sought to circumvent government controls on the Chinese yuan.

Consumers had rushed into bitcoin, which isn't controlled by any government or central bank.