The Department of Homeland Security's independent Office of Inspector General has taken up the formal investigation into the leak of confidential government information in late June that forced Immigration and Customs Enforcement to call off a nationwide operation, according to the federal agency.

“Last month, U.S. Immigration and Customs Enforcement (ICE) became aware of an apparent leak related to a planned enforcement operation. Leaks of law enforcement sensitive information jeopardize the safety of ICE officers and agents who have sworn an oath to uphold the law. ICE referred the incident to its Office of Professional Responsibility, which, in accordance with its normal procedures, referred it to the DHS Office of Inspector General," ICE said in a statement issued Monday morning.

The Washington Examiner was first to report on Friday that then-acting ICE Director Mark Morgan’s team had reported the incident to the ICE Joint Intake Center so they could investigate.

“There is an ongoing investigation. An internal investigation has been launched,” one official said in a phone call Friday.

The investigation, which is not a criminal probe, is centered around acting Homeland Security Secretary Kevin McAleenan, the leader of the department’s 240,000 employees, as well as at least one aide, for possible involvement in the leak.

"Everyone knows who they are investigating. Why didn't the acting secretary call for an investigation?" a senior official told the Washington Examiner on Monday.

McAleenan was named by three senior administration officials and two former officials as the orchestrator of the leak. These sources charged he wanted to sabotage ICE’s months-long plan to find and arrest around 2,000 people who had been denied asylum and not left the country. McAleenan opposed the plan because of its potential to remove a parent from a household with children in it.

Three officials have claimed McAleenan ordered Morgan on two occasions in the two weeks leading up to the planned June 23 operation to not carry it out, orders that would have contradicted the White House’s support and approval. Morgan contacted the White House following McAleenan’s warning to try to carry it out, according to three current and two former senior administration officials.

He directly denied being the leaker during an interview with Fox News host Laura Ingraham two weeks ago, but last Sunday dodged the same question when it was asked by ABC News host Martha Raddatz.

“I find it interesting that he demanded an investigation into the Border Patrol Facebook, but he didn’t demand an investigation into the leak. If he was innocent of this, why didn’t he?” said a senior former official.

The official was referring to a Facebook page on which Border Patrol agents made vulgar and derisive posts.

The planned raids in cities such as Los Angeles, Miami, and Houston, were first reported by the Washington Post the day after its reporter traveled on a government plane with the acting secretary and aides to the border.

ICE carried out raids nationwide this past weekend, though reports suggested they were not of the magnitude anticipated.