A construction union official and his union have been fined $24,000 after he racially abused a site representative on a Western Australian construction project.

The federal court handed the Construction, Forestry, Mining and Energy Union (CFMEU) a $20,000 penalty and official Bradley Upton a $4,000 fine after what it described as “disgraceful behaviour” in October 2012.

Upton made “obscene remarks” to one site representative and challenged another to hit him, after he became angry about a meeting room assigned for talks with workers.

On a second site visit Upton walked into an out-of-bounds area, despite being told he could only remain in the meeting room.

The court praised the site representative for his self-control and for not retaliating against Upton.

The fair work building commission’s director, Nigel Hadgkiss, described the behaviour as appalling.

“We continue to see the CFMEU and its officials take the law into their own hands,” he said in a statement on Sunday.

To date the CFMEU and its affiliates have been fined more than $6.1m in cases brought by the commission and previous agencies, the statement said.

Comment was being sought from the CFMEU.