Embattled union boss John Setka has slammed the arrest of a colleague, accusing police of unnecessarily storming a family home as part of a fraud investigation.

Police conducted dawn raids on the Construction, Forestry, Maritime, Mining and Energy Union senior official’s home in Melbourne’s north-west on Friday.

In a statement, Mr Setka said the raids were “unwarranted”.

“Having experienced first-hand the trauma inflicted on my family through the use of excessive force, these actions are completely unwarranted,” he said.

“This is something no family should ever experience.”

CFMMEU official Derek Christopher and a 44-year-old woman were arrested at a Keilor Lodge home early on Friday morning as part of an ongoing Victoria Police and Australian Federal Police investigation into building industry fraud.

A 52-year-old woman was also arrested at a Keilor property and all three are being interviewed.

Computers, phones and paperwork were seized.

The union said police used excessive force, storming into Mr Christopher’s home wearing balaclavas and carrying automatic weapons.

“The actions of the police have unnecessarily traumatised the family, including a number of young children,” the union said.

According to the CFMMEU, Mr Christopher had offered to help police in their investigation for the past 12 months.

Last month, officers also interviewed six men and a woman over solicitation of a secret commission. Those people are expected to be charged on summons.

Mr Setka continues to stand firm against widespread calls for his expulsion from the Labor party over domestic violence convictions and unproven comments about an anti-domestic violence campaigner.

-with AAP