A federal prosecutor in Minnesota has been dismissed while investigating an Immigration and Customs Enforcement (ICE) officer. Four sources familiar with the situation informed CBS News about this development.

Assistant U.S. Attorney Matthew Evans was leading an investigation into ICE officer Christian Castro. The focus was on the shooting of a Venezuelan immigrant earlier this year. The Justice Department has charged Castro with making false statements about the incident. The indictment details remain sealed.

ProPublica reported that Evans informed attorneys for Julio Cesar Sosa-Celis, the immigrant, and other victims to expect charges against Castro that involve making false statements. These charges imply lesser penalties than charges involving violations of constitutional rights under color of law. ProPublica referenced an email from Evans, claiming: This is being directed by the Main Justice and the US Attorney. I objected strongly and fought hard. It wasn’t enough. CBS News has not independently reviewed this email.

Three sources revealed to CBS News that Evans is under investigation by the Justice Department. Two of these sources pointed to allegations regarding information leaks as the investigation’s focus.

CBS News has attempted to reach Evans for his comments. This situation remains a developing story; updates will follow as more information becomes available.