Maryland’s Democratic senators want a Senate committee to require disclosures of foreign investments in U.S. election systems, an alarm bell set off by a Russian oligarch’s connection to their state’s voter registration system.

The request to the Rules and Administration Committee comes from Sen. Benjamin L. Cardin and Sen. Chris Van Hollen. Van Hollen is also the chairman of the Democratic Senatorial Campaign Committee.

[Mueller report: Russia hacked state databases and voting machine companies]

The Maryland senators have been alarmed by a Russian oligarch’s investment connection to ByteGrid LLC, which handles the Old Line State’s voter registration database and candidate management operations.

“As the Rules Committee prepares to mark up the Secure Elections Act, we respectfully request that you sponsor an amendment requiring that an election infrastructure vendor submit a report to the Chair of the [Election Assistance Commission] and the Secretary of [the Department of Homeland Security] identifying any foreign national that directly or indirectly owns or controls the vendor, as well as any material change in ownership resulting in ownership or control by a foreign national,” Cardin and Van Hollen wrote Monday.