U.S. law enforcement groups continue to push back against a key provision of the Clarity Act, warning that Section 604 could create gaps in oversight and make it harder to investigate and prosecute illicit crypto activity.

In a joint letter sent Tuesday to the Department of Justice and the White House, the groups argued that the language in Section 604 contains broad exemptions that could shield individuals or entities that facilitate the movement of crypto assets from regulatory accountability.

"Our concern is not with individuals who merely write or publish software code, nor with responsible technological innovation," the letter said. "Rather, our concern is with broad exemptions that may shield individuals or entities whose activities facilitate the movement of digital assets, create obstacles to legitimate oversight, or weaken longstanding investigative and enforcement authorities relied upon by law enforcement."

The letter was signed by four organizations: the National District Attorneys Association, the National Association of Assistant United States Attorneys, the International Association of Chiefs of Police, and the National Sheriffs' Association.

The groups also argued that several other provisions of the bill would "reduce transparency, limit accountability, and create gaps" in the anti-money laundering framework.