John Setka’s war on perceived enemies in his own union has intensified after he hired a former homicide squad detective to conduct an investigation into who leaked information against him.

The move prompted one CFMMEU official to say Mr Setka had “lost the plot” as divisions within the union deepen over Mr Setka's determination to hang on to power.

Former Victorian Police homicide detective, now private investigator Stephen Curnow has been emailing senior CFMMEU officials as part of an investigation into the leaks against Mr Setka seeking information about the “unauthorised disclosure” of confidential documents within the union.

John Setka after meeting Sally McManus in Melboune in June. Credit:Eddie Jim

At the same time, a 14-page dossier has been circulated to union officials around Australia this week that includes graphic details of the police case against Mr Setka over his alleged harassment of his wife, Emma Walters.