The Australian Federal Police believes a criminal offence may have been committed in relation to leaks about raids on union premises that are linked to Jobs Minister, Michaelia Cash's, office.
The AFP is continuing investigations into the leak of information, which led to media being informed and arriving before police raided the offices.
Deputy commissioner, Leanne Close, says dozens of people had been interviewed during the investigation, but is refusing to say if government ministers including Senator Cash had assisted police.