A Korea Customs Service official was found to have leaked a government press release announcing a package of measures aimed at curbing cryptocurrency speculation earlier this week, officials said Friday.

The government launched an investigation after a draft of the press release was leaked online hours before the official announcement of regulatory measures Wednesday. The leak is believed to have impacted cryptocurrency trading.

According to the Office for Government Policy Coordination, the draft was first produced at 9:37 a.m. for a meeting of senior officials from related ministries set for 10 a.m. Its file was then circulated among finance ministry officials for review.

One of the finance ministry officials then handed it over to the Korea Customs Service official for review. That official shared it with other agency officials through an online group chat before one of them posted it to another group chat involving reporters and other civilians, officials said.

The government will take disciplinary measures against those responsible, officials said.

Wednesday's measures came amid signs of overheating in cryptocurrency speculation and included such restrictions as barring minors from trading cybermoney and opening investment accounts, and prohibiting local financial institutions from possessing, purchasing and investing in the virtual currencies.

Cryptocurrencies, such as bitcoin and ethereum, have rapidly gained popularity in recent years. South Korea is home to one of the world's largest bitcoin exchanges, with about 1 million people estimated to own some of the best-known digital currency. (Yonhap)