Sen. Ted Cruz, a Texas Republican, speaks during a hearing for Judge Neil Gorsuch before the Senate Judiciary Committee in the Hart Senate Office Building on Capitol Hill March 20, 2017 in Washington, DC.
CNN  — 

An intern for Texas Sen. Ted Cruz was arrested on Monday after US Capitol Police found shotgun shells in the back of his vehicle.

According to a statement from US Capitol Police provided to CNN, officers were called to a “dispute” between the intern and another individual in a vehicle near the US Capitol. Officers observed the unregistered ammunition in the back of the vehicle and arrested 20-year-old Scott M. Frantz around 3 p.m. ET, according to the report.

He was charged with possession of unregistered ammunition, which violates the District of Columbia’s strict rules regarding possessing firearms and ammunition.

CNN has been unable to contact Frantz for comment.

A law enforcement source told CNN that Frantz worked as an intern in the Republican senator’s office. He was placed on leave from the senator’s office following his arrest, according to a Cruz aide.

CNN asked Cruz for a comment on the arrest on Thursday, but he referred all matters to his press office.

A spokeswoman for Cruz, Maria Jeffrey, told CNN in an email: “Our office does not comment on pending law enforcement or personnel matters.”

CNN’s Veronica Stracqualursi contributed to this report.