Fritz Zurbruegg, vice chairman of Swiss National Bank, the country’s central bank, has said that documents of Facebook’s proposed cryptocurrency, Libra, are “very vague.”

The central bank is in close contact with relevant authorities, but “at the moment, it’s difficult to perform a full analysis (of the project) because the available documents are very vague and details are still missing,” Zurbruegg said, according to a Reuters report on Tuesday.

The official made the comments at an event in Zurich city, adding that how national and global regulators handle the project remains a critical point.

Facebook announced the Libra project in mid-June and has since faced intense regulatory scrutiny from around the world. Facebook's blockchain lead, David Marcus, recently assured senators and other lawmakers in the U.S. that Libra won't launch until all concerns are addressed.

In other news, the Libra Association today launched a bug bounty program for all, which pays up to $10,000 in rewards for discovering the “most critical” issues in the Libra blockchain network.