Donald Trump’s Department of Justice is examining allegations that Corey Lewandowski used his top position at the Department of Homeland Security for personal financial gain, according to a new report.

The investigation, first reported by The Wall Street Journal , follows a referral from the DHS inspector general and marks a rare instance of Trump’s Justice Department probing an ally.

People familiar with the inquiry said the investigation was focused at least in part on potential contracting fraud. Lewandowski served as a top adviser to then-Homeland Security Secretary Kristi Noem in an unpaid role as a “Special Government Employee” — a designation meant for temporary outside experts — before both were ousted from the department in March following internal disputes and questions over agency spending.

According to sources familiar with the matter, internal investigators examined contracts approved during Noem’s tenure and found that Lewandowski was directly involved in signing specific agreements despite…