Washington DC - President Donald Trump's administration has reportedly launched an investigation into Corey Lewandowski, the former top aide to ousted Department of Homeland Security Secretary Kristi Noem.

According to The Wall Street Journal, the Department of Justice is looking into allegations from the DHS inspector general that Lewandowski profited from his position at the department.

Lewandowski served as campaign manager for Trump in 2016, and in the president's second term, he served as an unpaid advisor to Noem.

During their time together, Noem and Lewandowski were accused of berating staff, giving polygraph tests to employees they didn't trust, flying around together in a luxury 737 MAX jet with a private cabin in the back, and unreasonably firing employees.

Donald Trump Trump fumes over LeBron James warming up during national anthem: "He's no good"

The two – both of whom were married to other people at the time – were also rumored to be involved romantically.

Shortly after Noem was fired from her position, DHS announced that Lewandowski "no longer has a role" at the department, but did not reveal why.

On Thursday, when Trump was asked about the investigation, he didn't defend Lewandowski and claimed, "I don't know exactly what it is."

"All I know is, I want my people to be honest. And if they're not going to be honest, they have to be prosecuted," Trump said, adding, "I'll have my DOJ go and do whatever they have to do."

In a statement to AP News, an attorney for Lewandowski said their client "has not been contacted by the Justice Department regarding any investigation, and he denies any wrongdoing when he was proudly serving his country in a voluntary capacity."