Prime Minister Tony Abbott says his royal commission into union corruption will not conflict with existing criminal investigations or cases.

Mr Abbott announced the royal commission on Monday after a series of recent media reports about union bribes, kickbacks and links to organised crime.

He says the commission’s work will not conflict with current cases before police or the courts.

“There’s no reason that this royal commission should interfere with any of those,” Mr Abbott told ABC radio on Tuesday.

He also defended setting up two royal commissions, including another into the former Labor government’s botched home insulation program.

“It’s important to learn the lessons of past mistakes,” Mr Abbott said.

“Where you’ve got systematic wrongdoing, a royal commission is the best way to expose it and change the culture.”