The U.S. Treasury Department’s top lawyer sold off up to $30,000 worth of bitcoin in December, a month after Secretary Steven Mnuchin said the department was looking “very carefully” into illegal uses of the cryptocurrency, according to financial disclosures.

Brent McIntosh, a former Sullivan & Cromwell partner who was confirmed as Treasury’s general counsel in August, reported two sales of bitcoin in December, valuing each at between $1,000 and $15,000, according to disclosures released by the U.S. Office of Government Ethics. The sales came at the end of a year that saw bitcoin’s value skyrocket from about $1,000 to a high of nearly $20,000.