John Setka faces court over alleged threatening messages

John Setka was charged with sending threatening emails to the CFMEU's administrator last year. (AAP: Julian Smith)

Former CFMEU boss John Setka has faced court on charges relating to alleged abusive messages sent to the union's former administrator.

Lawyers for Mr Setka told the court he had been the subject of death threats, which police were investigating.

Mr Setka is on bail and is due to return to court at a later date.

Expletive-ridden text messages allegedly sent by former construction boss John Setka to CFMEU administrators have been made public in fresh court documents.

Mr Setka, 61, today appeared in the Melbourne Magistrates’ Court where he has been charged with 10 counts of using a carriage service to menace or offend and one count of committing an indictable offence while on bail.

During a brief administrative hearing, lawyers for Mr Setka told the court he had been the subject of death threats, which police were investigating.

John Setka allegedly sent a number of threatening, offensive and abusive emails. (AAP: Stefan Postles)

Fresh charge sheets released by the court now reveal the nature of the threats the former union boss was accused of levelling at former CFMEU administrator Mark Irving KC .

The court documents allege that in October last year, Mr Setka contacted a union administrator on nine occasions with expletive-laden email and texts.

In one email allegedly sent on October 27, Mr Setka told an administrator to get their noses "out of albos ass [sic]".

He allegedly followed up on October 28 with another email urging an administrator to organise for Prime Minister Anthony Albanese to have a colonoscopy “because that’s how far up his arse you dogs are”.

John Setka is the former boss of the Victorian CFMEU. (AAP: Joel Carrett)

On October 30, Mr Setka allegedly sent a text message which told an administrator to "go and f*** your mum … and leave me alone you f***in fat ugly c***".

Until now, the nature of the threats allegedly levelled by Mr Setka have only been briefly aired during a Queensland commission of inquiry into the CFMEU in November last year.

During the hearing, prominent anti-corruption barrister Geoffrey Watson SC, who authored a damning report into the union, told the commission Mr Setka called him a "f***ing fat, ugly c***".

The charge sheets released by the court allege that on October 30 last year, Mr Setka sent two texts calling an alleged victim a "f***in fat ugly c***" and telling them to "get some liposuction on your fat neck and get a lap band for your stomach and one for your mouth, you f***in dog