The royal commission into trade unions has heard the presence of two union delegates who did little or no work on a construction site was the price a labour hire company had to pay for industrial peace.

In evidence to the commission hearing in Brisbane on Tuesday, the Queensland construction manager of Hindmarsh Construction Australia, Ian Busch, said two union delegates representing the Construction, Forestry, Mining and Energy Union and the Builders Labourers Federation failed to provide any or as much labour as other workers.

He said he was told the presence of the union delegates on site "was the price of industrial peace".

Later, when the CFMEU and BLF merged, Mr Busch asked for the union delegation to be reduced from two people to one. He said an organiser for the BLF told him the BLF delegate would leave the project.

But, three months later, in April this year, neither of the union delegates had left the project, a 14-floor apartment building called Brooklyn on Brookes in Fortitude Valley, Brisbane.

Counsel assisting the royal commission, Jeremy Stoljar, said a water leak in the lunch room on the construction site was soon cleared did not cause a safety risk. Yet the union delegate who was nominated to leave the site told workers it was closed and sent them home.

Hindmarsh then notified its subcontractors it would not pay workers for the day of unlawful industrial action.

As a result, industrial action continued through April. Mr Stoljar alleged the union accused Hindmarsh of trying to get rid of the union delegate it had earlier nominated to leave.

Mr Stoljar said the union threatened further industrial unrest if workers were not paid for the day of strike action.

He said the union delegate, who was nominated to leave the site, was asked to do work as a hoist operator but allegedly refused, saying he was too busy.

When he refused to do the work, Hindmarsh asked for him to be removed from the site. This led to further industrial action, with no work done for another two days.

Hindmarsh obtained an order from the Fair Work Commission to stop the industrial action but it was ignored.

Mr Stoljar said the industrial action escalated when Mr Busch did not guarantee the return of the union delegate. The union allegedly threatened further action if Hindmarsh refused to provide a good reference for the delegate.

Mr Stoljar said the royal commission would consider whether criminal laws had been breached.

The royal commission also heard allegations that Queensland construction workers allegedly claimed hardship payments from their redundancy fund to cover unlawful strike action in 2012.