The Victorian boss of the Construction, Forestry, Maritime, Mining and Energy union is due to face court next week, after police were called to an incident at his home on Boxing Day.

Police confirmed a 54-year-old West Footscray man had been bailed to appear at Melbourne Magistrates' Court on January 9, after an incident at a private residence.

It's understood Mr Setka has denied being physically violent during the incident.

In a statement posted to Twitter, Mr Setka said he and his family had been placed under "enormous strain" in recent years.

"For well over thirty years now I have dedicated my life to the health and well-being of construction workers and their families, and on more occasions than I care to remember, my passion and bluntness has landed me in the headlines and not always for the right reasons," Mr Setka wrote.

"Over the last three years my wife Emma and my children David, Kate and Johnny have suffered immensely from the ongoing political and ideological attacks on myself as a union leader, with the possibility of losing their husband and father to a prison sentence. This has been an extremely enormous strain on our family unit and it has taken its toll on each of us as individuals.

"I ask that while family members are seeking to recover from this tumultuous period in their personal lives that they are given the privacy to do so."

In May 2018, prosecutors dropped blackmail charges against Mr Setka and his deputy, Shaun Reardon, which Mr Setka described as a politically motivated witch-hunt intended to criminalise trade union activity.

The CFMMEU was tight-lipped on Thursday, but it's understood members are sticking by their embattled leader, who is on leave.

With a federal election only months away, the latest controversy involving the CFMMEU places pressure on opposition leader Bill Shorten to disassociate himself from Mr Setka.

But his office would not comment on the matter. Asked whether federal Labor continued to support Mr Setka's position as the Victorian CFMMEU boss, a spokeswoman for Opposition Leader Bill Shorten would only say: "we won't comment on a matter before the courts".

Mr Shorten told the triennial ACTU conference in July that unions would have a "rightful and respected place" in a government he leads.

A spokeswoman for the Victorian government said: "as this matter is before the courts and subject to ongoing investigation it is not appropriate to comment."

ACTU boss Sally McManus could not be contacted for comment.

Ms O'Dwyer said the allegations made against Mr Setka were "very disturbing".

"John Setka is probably the number one supporter of Bill Shorten and his government," she said.

"Bill Shorten relies on John Setka and the militant CFMEU for leadership votes and for donations and every single time Bill Shorten has failed the test of leadership when it comes to the militant CFMEU and its leadership, but today he can't fail that test again.

"Bill Shorten must tell John Setka to resign his membership of the Labor Party and to resign his leadership of the militant CFMEU ...This is not a man who should be leading one of the biggest unions in Australia."

Last month Mr Setka angrily dubbed former prime minister Kevin Rudd a "f.....g dog" and a "maggot" at the federal Labor conference, as Mr Rudd prepared to accept life membership of the ALP.

Mr Rudd responded by calling Mr Setka a "blight" on the Labor Party and trade union movement, and saying it was a "minor badge of honour" to be attacked by the Victorian division of the union.

- with Nick Toscano