The immigration department has decided to let the person involved in the leakage of the confidential government refugee documents face imprisonment as punishment.

The Australian Federal Police have been asked to investigate the whole matter and find out how a confidential draft relating to national security leaked to the ABC’s Lateline program last week. The documents contained proposals for toughening the screening and monitoring process of refugees.

According to The Australian, in a Senate estimates hearing on Monday, Immigration Secretary Michael Pezzullo confirmed that the document was prepared secretly by the department and was a “pre-exposure draft.” The confidential proposals were only sent to other departments for feedback. A “sensitive,” “protected” and “Cabinet” labelled copy of the leaked document contained proposals to formulate new measured and make sure extremists remained out of Australia. According to reports neither Immigration Minister Peter Dutton nor Prime Minister Malcolm Turnbull had seen the document.

The secretary denied commenting on which departments that knew about the documents. He added that the matter has been transferred for investigation to the police on Friday. He could not specify the manner in which the investigation would take place, but he indicated imprisonment as punishment for whoever was found guilty of committing the breach.

“It’s a serious breach. It’s criminal and people could go to jail,” Pezzullo said as quoted by the ABC.

Deputy Secretary Rachel Noble claimed that a department officer discussed the document proposals with one of the advisers of Dutton on January 27. He mentioned the process and timeframes mentioned within it. During the hearing, it was confirmed that the inquiry might take a long time as it was necessary to gather sufficient proof to prove the crime. The public servants who are found guilty of leaking the confidential government refugee documents will possibly face jail years.