The Federal Reserve does not have the authority to regulate or supervise bitcoin, Fed Chair Janet Yellen told lawmakers Thursday.
Yellen added that she thinks it's appropriate for Congress to examine the regulatory structure for the virtual currency.
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Since bitcoin lacks a central issuer, it is not easy to regulate, she told the Senate Banking Committee.
Still, the Fed is looking into issues surrounding bitcion. This week, the currency was thrown into turmoil following the shutdown of Mt.Gox, a major exchange for the online currency.
—By CNBC's Katie Little. Follow her on Twitter